However, partnerships, S-corps, and C corps require an additional tax filing, plus there are wage considerations that go along with the S-corp and C-corp designation, all of which you might not feel is worth the effort of managing.My advice is to schedule time with a tax pro who (a) has expertise in business returns (not all of them do), and (b) does tax planning (not all of them do) and have them help you map out some scenarios to decide what structure will best fit your goals and strategy.

I decided to try to find deals off market.

Tenant screening starts in that first phone call, you may decide after that first phone call that you are wasting your time with said applicant.   

Hello, I am currently deciding whether to add a bathroom to a Victorian flat we will be putting on the market for rent.

(2) If the market decides to take the elevator down, what would I do?

I decided to try to find deals off market.

Or you can go shovel and pick up trash yourself, then decide how much it is worth. 

There is no move In check list, so I am afraid if I make them unhappy with all these changes and they decide to leave, they could trash the place and just say everything was like that before (when I toured the home they had already blamed some things on someone else).Is this a valid fear?

As an investor of more than 20 years, I can say that I have never once given any thought to the mortgage lender when deciding the numbers to offer.

Finding things any experienced person should have seen and expecting a credit (Front door worn) is another.Good luck in whatever you decide.