I only recently started really taking charge of my life.

Start with a cheap, single family in Ohio and learn.

Mortgage lenders have to sell these loans on the secondary market to avoid massive interest charges to their short term (warehouse) lines of credit, and allow for the liquidity needed to continue lending to the next guy... its kind of just how their world continues to go around. its rare these types of things happen, but it does happen. 

A single person can profit $250k without paying taxes. 

Are they single family or condos ?

I have a single family rental property in PA that I'm trying to refinance into a DSCR Loan.

How much can I possibly charge?  

I have and I have regretted it every single time.

I could say "no" to requests like someone getting a cat or something, or post a demand for rent notice if someone was late, and all I would say was "sorry, company policy is to post notice and charge the late fee every time rent is late, no exceptions".

He's bought over a dozen single family properties over the years (for vacation homes mostly) and he said every single time he just called the listing agent directly and got it done.I know most people generally frown upon this because the buyer agent is supposed to help get a better price, negotiate based on issues w/the house, etc.