You also have options like 30 Year Fixed, 30 Year 5/6ARM, 40 Year and Interest only (maximizes cash flow).You are essentially acting as your own bank by using the equity and selecting the best rate/term to benefit cash flow.

Overall Cost-Effectiveness: Is there any real financial benefit to taking this route, or is it essentially the same as just selling?

The 2nd reason to stay away from park owned homes, is that you lose the advantage of the MHP, which is essentially a trapped tenant, because they own their house, and they cannot move it, you have a guaranteed renter. 

Essentially what commissions are owed? 

@Hai Loci'm contemplating something similar; i can get 80% LTV. i bring in a cash partner for the downpayment on an investment property we turn into a vacation rental.let's say the pp is 100k.1. partner puts in 20k (and has this as lien on mortgage)2. i manage the vacation rental over the summer.3. we split cash flow (with property management fee considered).4. then we split equity  .is this essentially what you're outlining above?

So essential he just made a 10% return on his 100k for example if he let me borrow 100k. 

My parents are essentially giving me 3 homes to tackle myself.  

PM me pls Its hard to say - a broad range of things but essentially not disclosure issues and wanting things fixed that they didnt ask for after their first inspection.

Researched Youtube videos to find ideas (which are not very practical) 3.)

It's unclear if the state will champion this issue, but reaching out to your representatives is essential.