There is residential diagonally cross the intersection so perhaps that would help.

In which case go over the floor diagonally, or criss cross pattern type thing to help remove and level the floor.

I was thinking the same (i.e. income to rental and purchase pricing vs. non parity, in various cities and enclaves) with perhaps a disproportionate ratio of 'rentals' to home ownership... if that sort of data is tracked, and available online? 

Same for the diagonal cracks.If all the doors and windows fit and close properly, I doubt you have any serious problems, and after twenty years, the house is probably mostly done settling.

Darren:I know of folks who have used these loans to buy vacation properties (which some of them rent out when they are not using them), but no one else who has explicitly purchased a 2-4 unit as exclusively a rental.We used the Canadian LoC because the CAD was at parity with the USD and LoC was at prime (3.0%) a full 2.0% better than the mortgage rate we were quoted.

Diagonal cracks on the walls around windows and doors. 

A block may be split with a diagonal line, the top gets a check mark when a function has been achieved, the bottom of the box gets another check when another function is completed.

The crack diagonally spans the entire window, from top left corner to bottom right corner.

After it's clamped measure diagonally from corner to corner to make sure it's 'square'.  

If all you want to do is offer parity in perceived value and asking price you'll always have a difficult time, no matter the location or the market.