Is there a proper vapor barrier or radon mitigation system installed if needed.

I was planning on converting it to a SDIRA and buy a rental once I see whether or not I stink at picking rentals and being a landlord - I don't want to vaporize my IRA.

You may have a condensation problem if there was a vapor barrier between the plaster and sheetrock.

If not, I'd fill in the missing pieces and have the vapor barrier down, which is the practice in my area.

How about putting down some vapor barrier plastic?

The term “smoking” means inhaling, exhaling, breathing, or carrying any lighted cigar, cigarette, or other tobacco product or similar lighted product (Including but not limited to e-cigs and vaporizers) in any manner or in any form.

Also this building was built without any kind of a vapor barrier,  just T-111 siding right over the studs. 

Maybe 6 hours labor for crawl space + add in a vapor barrier.   

This is some prefab construction built circa 1960, if I'm not mistaken First, I would go with a plastic six-mil vapor barrier.

Would have still worked great as a BRRRR but with everything going on, we decided to cash out now so we can chase bigger stuff.Here are the key stats:- 2/1, 945 SF house in Sans Souci neighborhood of Greenville, SC- Purchased from a wholesaler for 65K cash- Final rehab budget came in at 57K - basically new everything minus the major systems, had to replace subfloor/ a few joists in bathroom due to previous leaks, removed a wall between kitchen and living room, new appliances (minus fridge), new patio, privacy fence, removed trees, vapor barrier, insulation in crawl space, etc)- Sold for 160K in 3 weeks- Netted about 24K after holding costs, commissions, closing costs, etc- Entire process (initial purchase to closing) took about 6 monthsBiggest lesson learned: we did too much!