AND THE MOST IMPORTANT PART,  document all communication and decisions about the repair requests.

Is it a legal 3-family on the city card?

If not, even though you are a re pro, losses are passive & deductions are limited.There are 7 scenarios that will qualify as material, and you only need to meet one:*500 hours*Substantially all participation*> 100 hrs and at least 1/2*Significant participation*5/10 years*Personal service activity w participation in last 3 years*Continuous participationTo materially participate, you must be involved in the operations of the activity on a regular, continuous, and substantial basis.Once you pass the pro test, the material participation often comes along for the ride.You can elect to aggregate all rental real estate for purposes of measuring material participation under Sec. 1.469-9(g).Your time spent on all your rental properties (STRs don't qualify) counts as one activity, making it easier to materially participate.In order to make a strong case with your CPA and the IRS you need to document your hours.Best practice is an hours log where you are as specific as possible.

I don't think it will be as simple as trying to just undo what the last owner did; you're going to need legal descriptions of each lot and that generally requires a survey. 

When you're on a temporary visa, especially without a clear path to permanent residency, the risk involved can be substantial—both financially and legally.

The only way is to document and possibly evict under nuisance.

This service also subs the legal work out. 

Is it legal for these officers to try to get inside my property?

https://www.biggerpockets.com/forums/51-tax-legal-issues-con...

In order to legally use the basement as a bedroom for you or someone else, the basement needs to have egress windows with a ladder to get out.