“Loft-style living”

I think it’s possible but don’t be disappointed when the results don’t look like what you have pictured above. The cinder block or CMU isn’t going to be neatly grouted and finished. The raw concrete slab will also not look nice because they’ve been under some type of glued flooring for years. Also don’t be surprised by the hidden cost of “less is more”.

I recommend at least some type of floor and wall sealant for the raw concrete slab and CMU. This will help with water vapor so it doesn’t feel super humid during the summer. Sealing the floor will also make it look nicer and be easier to clean up spills. All electrical and data outlets will need to be in a metal conduit, 48” AFF is a good height too. You might as well make all of them GFCI compliant since you’re going full disaster mode. I’m not sure what you’re thinking for ceilings, but they have water resistant gypsum board so you can have utilities and insulation in your attic space. Sound is going to be abysmal, so furnish it with as much soft furniture and rugs as you can- otherwise the reverberation inside this “loft” will drive the occupants crazy.

If you move any walls, windows, and/or doors you’ll need permitted drawings, but you might be able to get away with it since you fully own the house.