Asbestos in tiles is quite inert, especially if left undisturbed. Sanding is another story, so yes, you're wise to get it tested, but it sounds like you'd be unlikely to have been exposed just from being in the basement, doing laundry, etc. You could take some sort of swab sample of the dust in the ducting, I suppose, if there's even enough material to test. You'd need to consult with the lab in advance to make sure you'd get what they needed, and in an adequate amount. Most of the labs that test for asbestos commercially are looking at things like your tile and they are trying to tell if it is 1% or more asbestos, because that is regulated differently. You'd probably get a "non detect" result from your HVAC unless you went somewhere very specialized.

Typically when a homeowner has opportunity to go in to a basement or open a wall and see the distribution piping system they categorize it in one of three general categories, Galvanized iron pipe (GIP), copper pipe or plastic pipe. From this they generally infer that GIP was the norm at the beginning of the last century and up into the late 50's but it has by now probably exceeded its anticipated service life and would most likely be problematic. They then see copper and view that as a good installation and plastic pipe is generally viewed as cheap contractor grade tract home material. While most homeowners simply think copper is copper in fact nothing could be further from the truth. Primarily we have 3 grades of copper pipe, type K (heavy wall), type L (standard wall) and type M (thin wall). To offer a comparison let us consider the wall thickness of 1/2" copper pipe. For 1/2, the type K wall thickness is .049" while type M is .040" and type L is only .028". This standard remains the same for both Hard drawn (rigid lengths) and annealed roll copper pipe thus hard drawn and roll copper may be used interchangeably throughout the structure. (Be careful here though because there is a distinct difference between roll copper pipe and roll copper tubing.) When examining copper pipe you can determine the type of the pipe by reading the information printed on the pipe wall, whereas a trained eye can generally see it from a distance by looking at the color of the writing on the pipe. On type K pipe the writing is Green, while on type L it is Blue and on type M it is Red, however if you see blue writing you should check it closer because type ACR(Air conditioning & refrigeration pipe) is also labeled with blue ink. While all three grades of copper are approved for distribution piping the type L standard wall is generally preferred. Type K is generally considered overkill for water distribution and is generally only used in residential service for higher temp hydronic heating, low pressure live steam heating or fire sprinkler systems. We must also consider the age of the installation. If the copper pipe was installed prior to 1983 it is most likely installed with ASTM alloy SN-50 solder (50/50 tin/lead solder) whereas for all installations after 1983 it will be installed with solder conforming to ASTM alloy SB-5 certified "lead Free" 95/5 Tin/antimony solder or an equivalent". The next thing we look for is the evidence of what we affectionately call in the trade "ornamental solder joints". Ornamental joints are joints that show evidence of blobs and little grape like beads clinging to the joint which can indicate a "Cold joint" where the solder was not properly heated and probably did not fill the fitting correctly. Often you will see corrosion on the joints. If the corrosion is a greenish color that is simply copper patina and not considered a problem however, if you see evidence of a white powdery corrosion that can be evidence of a serious problem. In some regions they have acidic water and they have problems with pinholes in copper piping, however the problem is not nearly as common as some would have us believe. While pinholes can be a serious problem with water supplied from a home well, the ANSI/NSF standard 61 and the U.S. Safe Drinking Water act of 1996 require that all water supplied from a municipal water supplier MUST BE treated to provide a non corrosive neutral water supply. While there are instances of true pinholes in copper, what is more common is that the homeowner becomes aware of pinholes and while examining their piping they discover droplets of water clinging to the underside of the pipes and assume its pinholes. They then call a plumber to express their fears and ask what corrective action must be taken and sadly there are unscrupulous plumbers that seize the opportunity to convince the homeowner they should consider a whole house re-piping job using PEX, when in fact, all they really needed to do was insulate the effected pipes to prevent moisture in the atmosphere from condensing on the cold water pipes. (Within the last year there have been 3 plumbers in my region convicted of fraud for this very reason.) IN my opinion, if you suspect pinholes you should get multiple opinions before committing to an expensive rework job. Now in regard to your question about plastic piping. The answer here would totally depend upon what type of plastic pipe. When it was first introduced PVC was a very popular material and for a few years it was commonly used for potable water distribution, however it was learned that PVC did not hold up well for hot water service so for a short time PVC was approved for cold water lines but we had to use CPVC for hot water. Within a couple years most of the codes dropped PVC from the list of approved materials for distribution piping and inserted CPVC in its place however, even though PVC is no longer approved for distribution piping, there still remains many homes that were constructed in the 70's that have PVC throughout. This does not mean that you need to change it out, but it would be a strong consideration if you are looking to buy a home that was constructed during that period. Although it is nearly impossible for the homeowner to obtain today, when CPVC first came on the scene it was made to the same schedule 40 or schedule 80 IPS (iron pipe standard) as PVC pipe therefore both the pipe and fittings were totally interchangeable with PVC pipe. This often lead to the improper pipe or fittings being used for repairs. (the plumbi9ng codes expressly prohibit gluing dissimilar plastic materials together.) In order to prevent co-mingling PVC with CPVC the CPVC commonly available today is CPVC-CTS (CTS=copper tube standard). By making the CPVC in the CTS standard it eliminates the risk of mixing the pipe and fittings. If you live in a region where you do have acidic water and your water source is a home well CPVC would be the best choice because there are no metal components in a CPVC system that would be effected by the water conditions. On the other hand,if you have a water condition that would eat up your pipes, i have to wonder what the long term health effects of drinking that water would be. In my humble opinion under these circumstances the homeowner would be much better served by considering a water treatment system to correct the problem rather than look for a piping material that would tolerate it. now, while the IRC does still list Polybutylene pipe as approved for potable water distribution based upon the high incidence of failure in the fittings and the millions of dollars in class action lawsuits coupled with the fact that it is totally outlawed under the UPC, I don't know any plumbers that would be willing to risk the liability of installing it. for new construction today the materials of choice are primarily copper or PEX. When installed correctly PEX will provide a distribution system that would be equal in quality to a copper installation but the key here is, "When installed correctly". While pulling a continuous run of tubing through a structure is much easier than soldering a fitting at each change in direction, it must also be noted that PEX has its own set of installation characteristics and often they require much more attention to detail that what copper does. By example, I have a close friend who is in the final stages of completing a home which he has built by himself from the ground up. He elected to use the PEX manifold system for water distribution and during his rough-in inspection all of his tubing runs were inspected for proper hangers, correct turning radius on all bends and the fittings properly crimped in place. After he set all the fixtures he called for a final plumbing inspection. Four times the plumbing inspector came to his house, walked down the stairs into the basement, stopped at the foot of the stairs and said, I will be back when your finished with your installation, then he red tagged the plumbing and left. Finally my friend asked me to come and see if I could find the problem. I went to the bottom of the stairs where the inspector had stood, looked around and said, "Sorry, but your inspector is correct because I can see the tubing in the joist bays". Why you ask? Both the plumbing codes and the manufacturers installation requirements state that PEX tubing must be protected from UV light exposure. Whenever PEX is run where it will be exposed to light, whether direct sunlight, indirect sunlight or artificial light the tubing is to be sleeved in a UV barrier sleeve thus when run in a joist bay you must either sleeve the tubing or close in the joist bay and the manifolds must either be in a closed utility space, a cabinet or covered to protect them from light. And while on the subject of manifold systems. While many people think that a manifold system is confined solely to a PEX installation, such is not the case. There is nothing in the code that would prevent one from installing all piping systems in a manifold configuration, in fact the manifold system was commonly used on Polybutylene pipe systems in the 70's. Personally I don't care for a manifold system. I find it a total pain in the behind to be working on a faucet in an upstairs bathroom and have to go all the way to the basement to turn the water off instead of closing an angle stop under the fixture.

Good background check and credit history. Talk to previous landlords. No children doesn't always make for better tenants. If the house is in a good school district your family may become long term tenants with pride in their home. Try to get inside or next to their vehicle. It will hint at messiness and whether they smoke. You may not discriminate on the basis of kids or no kids in a single family home unless it is in a senior living community. California does not require that they have renter's insurance. You could strongly suggest they carry it. It is not expensive and most people will get it once they understand the landlord is never responsible for their personal property losses. Do get a good umbrella policy (liability insurance) to cover personal injury situations. You need to have that. If someone gets hurt on the property the lawyers go after the deepest pockets. You as the landlord are the deep pocket. Schedule regular maintenance checks without being intrusive. Three times a year is not excessive. Give notice you are coming. Respect that it is your house but their home. Put everything in the contract. Nothing verbal. Be sure to fill out all disclosure statements California law requires. Leave copies of appliances manuals. be sure they know how everything works. Do a walk-through before they move in. Take pictures and make notes of wear and tear. Expect to replace carpet and paint frequently. Your house is their home. Wear and tear is normal. Destruction is not. Never allow them to do their own repairs. Exception would be if he/she is a plumber and wants to fix the leak or a professional painter. Even then you must pre-approve everything. Every single time. Do not count on a property manager or realtor to give a damn. They don't care. It's your property not theirs. Invest in a copy of the California Landlord's Law Book. Also get the Tenant's version. Best $50 or $60 you'll ever spend.

As someone with experience in asbestos removal, I can say that vinyl asbestos tiles often become brittle over many years, and can fracture into a lot of pieces when you're trying to remove them. The Minnesota Dept. of Health web site has a lot of good info, but the assumption that one can "work under the edges of the tile and pop it loose" is not correct in some cases, especially where one is dealing with old tiles held tenaciously by black mastic. Old vinyl tiles are not like the "peel and stick varieties. We don't know how old the OP's tiles are, and, even if we did, the approach to such a situation can vary from site to site. I'm not trying to get in an argument over removal techniques, or say there is only one way to deal with this situation. But I am pointing out that slowly drilling some holes in vinyl tile with an encapsulant capturing stray fibers may be a better approach than thinking you can easily pop up some tiles. This is a case where one could try to remove tiles, end up fracturing them into multiple pieces, scraping at the mastic, and having a mess on your hands. I'm not holding myself out as an expert. I'm counseling the OP to look at a low-tech approach that may result in less risk compared to trying to do a "better" job by removing tiles.