When we spoke with the realtor he said that makes no sense because there are no cracks, [little fixable ones in the foundation] in the interior of the house [exterior has siding] and that the doors and windows are all squared and a marble on the counter does not roll.our understanding had been that there was only interior cosmetic damage.  

There is a house that maybe in foreclosure (or pre-foreclosure statue).

If the tenant complains that they wont be around to collect the funds in the mail, you can site the state statue that explains the law.

Can I ask what statues you are referencing to say option 1 is not viable on a single family unit?

Stick with your state statues, give the pay or quit,, follow up with filing for eviction.

No offense to the elderly (and I'm 64 years old myself) but dad doesn't seem like he's playing with all his marbles here.Unless you like drama, rent to the couple.Gail

If anyone has any suggestion or knows of any statues regarding a homeowner's right of being able to modify his property and rent it, or being required to get permits for all past work under the previous owner, I would greatly appreciate it!  

On outside may be man made statues.

The property has a 30" bathroom vanity that has deep scratches and stains on the cultured marble top and decent amounts of wear and tear on the body.

Also, it is up to you, but if the suggestion comes up, I wouldn't accept partial payment, even though it appears Wisconsin Statues appear to allow for this and still continue with eviction (Wis Statute Sec 799.40(1m) - https://docs.legis.wisconsin.gov/statutes/statutes/799/40/1m) (contact a lawyer, I am not a lawyer and none of this is legal advise).