Do I need to file anything with the county to make it official or will an appraiser just see the 4th bedroom and use similar comps?

That comes first.If your tenant has done any damage, it's already happened and it's likely not as bad as you are imaging.Some areas have eviction services where you can hire someone to handle the entire eviction process for you, from the very first step of filing and serving notices, to the court date, to the eviction day itself.

Irs and FTB definition:Eligible Small Business For purposes of the credit, an eligible small business is any business or person that: • Had gross receipts (including that of any predecessor) for the preceding tax year that did not exceed $1 million or had no more than 30 full-time employees during the preceding tax year, and • Elects (by filing Form 8826) to claim the disabled access credit for the tax year. 

A friendly attorney should be able to file a specific performance suit for a few hundred dollars.

@Daniel Liska in MI, a property management company must be licensed, so you could reach out to the department of licensing and regulatory affairs to file a formal complaint.

Thanks for the info, do you mean the recorders filing?

Should that occur, you can file for eviction.

You’d be much further ahead just collecting cash to pay expenses from the person instead of filing and claiming income hoping for a tax break or advantage .

Or is it better to file for eviction?

File an eviction notice for abandonment of premises.