LeBox, I'm sure you understand this is a complex issue. I can offer comments but not assurance that all important factors are accounted for. I hope you get a local review of your plan in order to prevent work being done that falls short of solving the problems. Let me mention some possible issues. In a large rainstorm, the volume of water running off the hillside could be considerable. As it will be caught in the swale at the top, back of the wall, the swale needs to be calculated to handle the volume of water for a large storm. As the swale is located at the north half of the property, would it be better to drain it off to the north side of the property instead of having it go the longer distance around the south end of the house? If possible, I would have the goal of keeping this surface water at the surface instead of putting it into a pipe. (Sometimes it's not possible.) If it's on the surface, one doesn't have pipes clogging in the middle of a storm and failing. If it must go in a pipe, the pipe needs to be calculated to handle the flow of the design storm. Frequently, homeowners think 4" pipe will do everything but it is often inadequate. You would not want to run this water coming off of the hillside into the existing drain system of the patio (feeding a larger pipe -- at least it should be -- into a smaller one.) You might end up doing the reverse ... running the patio drain into whatever drains the hillside surface. The section of the drain behind the wall looks fine. The purpose of the collector pipe behind the wall is only to get rid of water that infiltrates the soil behind the wall. You would not want to add any drainage water to it or simultaneously use this pipe to drain any surface water through it. Though you could drain this pipe into a larger pipe or swale that is draining surface water, so long as it is calculated to handle the volume. (The volume of the water collecting behind the wall will be small relative to the volume that is draining from the yard surface.) "Arms of surface drains extend to edge of patio w/riser" ... the only purpose I can see for these is as yard drains at the edge of patio, though I wouldn't know what volume of water to expect in this area. As yard drains, inlets would need to be slightly lower (2") than the patio surface with the surround grade pitched downward toward the inlet. This type of drain is subject to clogging from yard debris so requires regular cleaning of the inlet and possibly a cage over the drain to filter out debris. Usually, groundcover of some type helps to keep surrounding soil from washing into the inlet. Summing it up, you have 3 separate drainage systems: 1. swale behind wall ... this is largest volume of water. 2. existing patio drain w/ attached yard drains ... this is second largest volume of water. 3. collector drain behind wall ... this is least volume of water. lower volumes of water can run into systems handling higher volumes of water, but not the other way around.

OP described one way running bamboo can become a nuisance, by deliberate planting which still occurs in some places. However around here (midAtlantic) Golden Bamboo Phyllostachys aurea, is routinely dumped. Homeowners dig it up, take it to the local roadside and dump it. Left unchecked, it forms large colonies. I was part of a volunteer group that got together to rid this species from our park. The colony was about one acre. It took 4 workdays but we cut and removed it all. That was 4 years ago, sadly it has all come back with a vengeance. It really wasn't followed up on.Yours truly has started the process all over again. This pic shows recently cut stems painted over with 41% glyphosate (undiluted) Regarding foliar applications with either herbicide or vinegar/salt I have no experience. Normally with herbicide backpack sprayer temps must be 60 F or higher. Seeing how this is a bamboo forum it really cannot be repeated enough, Golden Bamboo really has no redeeming qualities. A large infestation of this Chinese weed on the property is a liability. ZERO wildlife value of any type. One USDA site says "birds & small mammals are reported to feed on seed". Anyone familiar with this species knows the fallacy in that statement. It may be that pandas eat the foliage, I'm really not sure. Either way that's not a justification for growing it here. To finish on a positive note, one can collect up stems and use them for fire kindling. They burn fast and hot, even when green. They will make popping sounds but not a real problem.

Thank you Rollie..love the way you break it down. It is amazing the difference it made years ago when sheet products became available. Prior to that walls/ceilings were made of individual boards..then all of a sudden 32 sq ft with no holes in them. Great for reducing air infiltration. With sheetrock you are sealing all the gaps where the rock joins and if you seal the penetrations you make a lot of air tightness can be achieved.Always seal wall to ceiling joints even if installing ceiling moldings. The detail work..sealing sole plates,around electrical outlets, dryer venting through walls..caulk is a great thing! In unvented attucs choosing ICAT recessed cans and not IC cans, sealing all gaps around bath fans.. stove vents ..fireplace vents this makes an excellent air barrier. Once the air barrier is complete then any insulation will perform better. what lowers R-value is air movement and misinstalls. I would recommend that you also insulate the bonus room area. In my climate these are problem rooms as they are surrounded by hot attic air..as opposed to exterior walls which are exposed to outdoor temps. Attics reach 140 degrees here. If you eliminate the foam in this area you will pay for not installing it in comfort and utility costs. It just doesn't make sense to me to not use the better method for the area where living space is in the attic... air seal then insulate walls conventionally roofline with foam. over bonus room also. savings from wall foam will pay for bonus room install best of luck,

Try www.buildingscience.com/ for information about vapor barriers. Another good source for local building advice might be your state land grant university. I do not know anything about your floor finish. I guess you will cringe when I mention pre-finished flooring, but keep reading ;-) The spaces between the boards lets moisture through. With finished in place floors (poly finishes) you have a good vapor barrier. I guess that you understand the "sandwich" prohibition now. If you have a vented crawl space, off gassing will primarily be through the crawl. Ignition is a good question. I am afraid that I do not know much about fire and foam. I know that it burns and that crawl spaces raise fire insurance so it is a good thing to look into. Any kind of covering over the underside of your floor is going to increase the risk undiscovered or delayed discovery of rodent and insect damage. That includes batts, foam or boxing-in with rigid insulation. I do not know if there is any hard information about the relative risks of each method. The rigid insulation alternative is not one that has been addressed in this thread yet. It would be less expensive than foam, if DIY, but it is a lot of work. It has to be taped very well. You could take a hybrid approach and cover selected areas with foam board -- under the most troublesome plumbing areas for example. When you get done with that, you foam the rest. Low density foam pulls out pretty easily. I do not know about high density. You would just have to spray some more in after you make repairs. The problem would be finding the stuff that you need to fix. I would considerer tagging stuff before foaming if it will be covered by foam. You could use durable plastic tags in some color code. If you have a leak, water will run right through low-density foam. I do not think that is so with high-density foam. One important feature of spray foam is the air-sealing capacity. Batts will not do that. That is the problem with it where I live in the humid Gulf South. Air gets around batts even when freshly-installed. It is even worse when it sags. Humid air hits the cool floor, water condenses and does not dry well. Floor rot happens. Even with the best batt installation, the joists become the coolest thing under the house. Condensation happens there and then rot happens. These things worked great before AC existed, but not anymore.