Again, I'm  using THIRD party property managers for all the mult-tenant properties so I really don't think it makes sense for me to use some gigantic program like AppFolio or Buildium.

Joe,Yes, you would do a bank statement program using gross deposits or use a DSCR loans. 

It depends on who the lender is and what type of loan product / loan program you're getting into.

In my area is in the additional dwelling units pilot program.

We help numerous clients with this program each month.

They have a program where they get a percentage of the bookings. 

Most park owners who are still carrying notes on homes they've sold are doing so with either a rent-credit program or a lease w/option program.

There should be some sort of regulation put in place for it.The best solution I can think of is to, I don’t know, have some sort of program or schooling where you could go learn how to fundamentally and legally sell real estate.

As pointed out in the above quote, yes, you're expanding your business model and your fortunes through leverage, and this will be jet fuel to your financial program.   

Did you ever find a good program?