Does this seem a little extreme here in my zone 5/6 Ohio? My first floor has R19. It's over Code. But Building Science Corp.'s Dr. Lstiburek's rule of thumb is that for any home north of the Mason Dixon Line, follow the 10, 20, 40, 60 rule. That's R Value for, respectively, basement slab, basement walls, above grade walls and attic. If you're planning to stay for awhile and the labour is yours, there may be an economic payback. The space will definitely be more comfortable. My biggest fear is trapping water with too much insulation. At Roxul sales displays, they like to run a water fountain through a chunk of their product. The water runs right through and is not absorbed. will my basement still be the coolest part of my house in the summer? Well, mine have been. But that's probably because of the leakage of HVAC-cooled air into the basement, where the cooling equipment is also located. Is it ok to just add fiberglass insulation without a vapor barrier, and close up with sheetrock? Unless you're in an extreme cold climate such as northern Alaska, leave the poly vapour barrier out. All you need is painted drywall as a vapour retarder. in the rim joist, I have 1" of closed cell foam covering the entire rim joist. Should I add XPS boards and seal, or just add unfaced fiberglass there as well? Either one works. See illustration below from Building Science Corp. Info. Sheet 511, p. 2.

1) Looks don't count. So cobble together what you can in those hard to reach spots and seal with polyurethane spray foam such as Great Stuff. 2) You are referring to adfreezing, that is the condition of soil freezing to the exterior of the foundation wall and then exerting upward pressure on the wall, leading to heaving and damage. The risk of adfreezing increases the more the foundation is insulated, which prevents heat from keeping moisture in the surrounding soil from freezing. The solution is not to stop insulating, but to: 1) use granular material as backfill, or 2) provide a slippery material on the exterior of the foundation, such as a bubble plastic membrane. (I even use it on the interior of attached garage foundations.) or 3) use a horizontal insulation to keep the soil from freezing. (See link, which recognized this problem more than 40 years ago, for further details.)

Sounds absolutely fine to me! 1)-3) No comment 4) The insulation will make little difference as far as sound proofing. If keeping the noise down is a big priority, use a damping system such as Quiet Rock, Green Glue or resilient channel and an extra layer of drywall. 5) If the heat pump doesn't keep humidity below 35% RH, you can always put in a portable dehumidifier. 6) If the inspector is uninformed and therefore insists on a polyvinyl vapour barrier, it won't hurt the system. There's no need to bother with Membrain, which is designed to be effective with fibrous insulation. On one project I did with cc on the walls, the inspector approved it without poly. On walls with XPS, inspectors have insisted on the poly.

If a room is "unconditioned" it should be insulated from any "conditioned" space that is adjacent to it or above (as required by the building code for new construction). Adjacent conditioned spaces do not need insulation in the walls or the floor-ceiling assemblies that separate them. If the adjacent rooms are not conditioned to the same temperature then insulation might help but wouldn't be critical or required by code.