At the very least have current landlord give the proper notice as required for increase and for the vacant unit non renewal.Get the clock started now vs when you close...

I am concerned about these upcoming repairs. 

I'd be more concerned about the business terms of the deal and the numbers.

Is there a good mortgage calculator out there that I could use to figure out the difference in costs between paying PMI at my current rate, versus dropping PMI, but having to pay an increased interest rate?

I want to purchase a multi-family (four plex) to rent out, but im concerned that if I get approved for a loan it hinder my future purchases for more multi-family homes.

I have read through many post concerning this but wanted to get a better idea/opinion of what we should do. 

You’ve got to find a way to bring more value to the marketplace  Agreed, use that savings to increase your W2 income.

Real estate investing and flipping has become increasingly popular because of the return on the investment and the ability to use other people’s money to do so with the intention to increase both parties return.

I would ignore any concerns you have about mental disabilities and just focus on the tenants' compliance with the contract.

Real estate investing and flipping has become increasingly popular because of the return on the investment and the ability to use other people’s money to do so with the intention to increase both parties return.