If they are able to get it turned around and making money (cash flow positive), they then grab another one using a low-down payment loan.

You have to remember you make your money when you buy the house .

Tenant/Buyer is required to put down nonrefundable option money.

Where can I go to borrow money to give the contractor in order to get the project started?

You can get creative with recasting mortgages, refinancing, etc. but at the end of the day these things cost you money. 

Your cost of living sucks in NYC so that hurts as well.You say you want financial freedom, but what you really want is time freedom and the only way to get time freedom is through earning money to give you that.

Currently I like the idea of having long term rentals for my future, but I really enjoy managing my place and think that I would enjoy doing property management as I would get to help others make money and help find a home for future residents.

If yes and yes money back or discount or sue and confirm they face penalties for failure to disclose and that they “remember” to disclose to next buyer. 

It’s way better than 5% on your money in the bank!

Where people get hung up is that much like a car, a new MH may lose value coming from the dealer in what you pay going into a park.