Yes I know besides a life I should get some sleep.
“Also, if she subletted one room, and “lived” in the other, could she still claim it as a primary residence?”
I think you are saying if she lives in the house she has title to and has a roommate can she fully call this a primary residence. Yes. I did this for years and my tax guy said the IRS didn’t want to hear about it because then I could start deducting all kinds of stuff and it would be a wash. The rules probably technically don’t read that way. At the level of economic impact we are talking about,my guess is that nobody cares.
Disclaimer, this is not tax advice this is shared experience only.
Most everything is covered by previous posters.Here are my opinions about the concerns on the condition of the house.
Most of these houses have issues. This is a very old neighborhood and forgive me for saying,also questionable housing stock. They sell all the time. You probably are not going to need to make any more disclosures than the next house and the next house “should be doing”. You are not likely to get in any trouble over unpermitted modifications and I doubt it would change the opinion of the person who would ultimately buy you house at all.If you sell your place definitely have a game plan for how you are going to negotiate around any repair concerns. You might want to put heavy emphasis on “as is” terms. A low LTV buyer might have some issues that have to be repaired due to lender program requirements, but those can usually be accommodated for by not being too flexible on price or alternately you might give a cash buyer a break.
Lots of these houses have water issues from surrounding apartment buildings.In city heights and surrounding areas clay exists right below the surface and the water floats right across the clay after it becomes saturated. Just disclose it.I would even say minimize the measures you have taken against it as much as you can without hiding it completely.This is not to say be dishonest . Just make sure you are not making a mountain out of a mole hill.