No mistake on plans, debating making it a office/nursery.  

And as far as police and firemen ..

I also look at the credit report and check the income to debt ratio as a loan officer would.

The absolute slam dunk is professional offices.

An informal probate would be available to a decedent who's asset total less than $150K.Ask you seller if the decedent owned other real property and stocks, etc. estimate what the total vslue of those might be (roughly) and then ask your title insurance officer what they require. 

Typically insurance agents advocate for umbrella polices while attorneys advocate for forming LLCs.Unless you have a ton of equity or cash, I would focus my attention and time on accruing more assets.That being said, it never hurts to plan ahead. 

If you didn't call the police to take the pot and document it, then you're likely not going to be able to use that as a basis for keeping the deposit.

Some Post Offices will allow you to list their physical address if you have a PO Box there.

Your tenants needed to escalate the issue immediately, regardless of the opinion of the responding police offers.  

If you call your local county building or sheriff's office they will be able to tell you what you need.