Ok, please do not try this without checking it out first. Here is my story. I had this problem more then once. The first time I got these crawly threadlike things in my soil (ie. Last summer), I ended up throwing out my Thanksgiving Cactus. So last November, I purchased a few more Thanksgiving Cactus from the supermarket. I noticed those pesky tiny fruit flies/knats flying around my plants. ( they usually lay their eggs in the soil ) Well that was it! I mixed a combo of rubbing alcohol and water and sprayed the surface of the dirt on my newly purchased plants really well. I have knat/fruit fly traps all over...ie.. Near each plant. For the first time since the Fall, I recently saw the first little bugger and put out my traps. I may do my alcohol/ water spray again. But this is risky. It did not kill my plants, but it can kill them if you overdo this. Proceed at your own risk. Best to try to control this problem. I do not think you can completely avoid it if you have live plants in the home. They LOVE organic soil and there may be unhatched eggs in the organic soil you buy at the garden center to transplant your thanksgiving cactus into a new pot in the Spring. So far I have NOT transplanted anything. Nor have I fertilized anything. These tiny fruit flies/knats come in through screens or with your groceries/fruit that you buy at your local supermarket. They can even come up out of the drain in your sink! I have added photos of these traps. They work well so far for me. You can purchase them at Home Depot or True Value Hardware.

The hyper heat heat pump can make sense to cool an area with difficult access for ducts. Does the basement fit that description? It will cost you more to heat it with a heat pump than with natural gas. What are the aims of zoning, saving energy or comfort? If the former, you are probably barking up the wrong tree. If you have a well-sealed, well-insulated home, your heat transfer rates between rooms/floors will be much faster than out of the structure. Zoning can be difficult to accomplish, but not impossible. With old-school high mass boilers, it was not so difficult, but a modern, low-mass boiler, if sized to heat a large area, will be shutting off frequently. The same may be true for furnaces, but I am not as familiar with that issue. I've seen you write boilers and furnaces, which are you looking for? You can do forced air heat with hydro coils powered by a boiler, or with a furnace. With a hydro coil, you might be able to heat the bonus room but you'd still need a way to cool it. Cost calculations would tell you if it is worth it to install separate cooling and heating systems there. What are you planning on doing in the basement? Is is going to be just one, open area? I'd consider hiring an energy rater to help you plan and set milestones for the builder. They can help you choose your mechanical systems appropriately. They can do blower door tests to make sure that the house is air-sealed and insulated properly. Where are you located? It can make a big difference in figuring out what kinds of equipment to install if you have to heat a lot vs. cool a lot or both. Humidity is an issue too.

You should get more helpful responses on the Name that Plant forum. There are some real ID whizzes there. You can just copy and paste your original post, photos and text, to the new spot. i am not sure what the plant is in the upper right of the first photo, but the one in the center with ferny leaves that is also behind the peony is most likely one of the weedier Artemisia. Does it have an herby scent when a leaf is torn? Regardless, it looks too aggressive to get along well with other plants, so I would start working to remove it. Anything growing near the peony or hosta needs to be removed, and at a time when you expect to have a few days of cool rainy weather or else this fall I would move the Hosta so it is a bit farther from the masonry since it looks like it will be too close. The shiny leafed groundcover in the last photo looks like it spreads fairly aggressively as well, so I would likely pot up a few to confirm ID when it blooms and remove the rest before it takes over everything unless you want an aggressive groundcover there. Right now it makes me think of Campanula punctata (such as Cherry Bells) which is a rampant spreader to the point of extreme weediness in many gardens. I am generally a fan of Campanulas though my soil is too acid for them to be entirely happy, but C. punctata is far too aggressive for me.

FYI: Stachys byzantina is an herb. Leaves are 'wooly', covered in fur-like hairs; stems tend to be 4-angled, and plants grow upright and tall. Your plant is a succulent, has smooth leaves and round stems.