The older you get the less attractive appreciation is unless the goal is to leave some kind of legacy. 

Where can I get the form to file? 

A landlord looks a t how much the property will make long term.A flipper looks at how much in a short term .

The insights I’ve gained so far have been invaluable, and I’m eager to expand my network and grow alongside other professionals in the field.

What are the biggest challenges people have faced with this.

@Garry LawrenceDevin Moreno has a bunch of videos on rent-by-the-room strategy in Baltimore on hisYoutube channel.

The mortgage would stay under the seller's name.The buyer could then rent out the unit, renovate, etc. to increase cash flow or make more money.But aside from a possible "due on clause" being called by the mortgage company, what's the benefit to the seller?

If you have evidence of the damage, it is unlikely the tenant will spend the time and money to take you to court.

Now he has one under his belt he can go out and use that framework to do the next one and the next. 

In that case you should get an attorney involved as encroachment would be a material issue that if known should have been disclosed both to the broker and to any potential buyer.