I have no skin in the game here, so don't take my word as actionable advice, just a perspective of how I would account for things.

If I go the financing route, my initial investment (25% down) would be less skin the game, which feels more comforting, but I would also lose cash flow to the lender.

Some lenders do specialize in rehab/fixer sort of loans and are used to working with flippers, however he probably needs some "skin in the game" like 25% of purchase price or something to actually close.  

I had to put a cover on an HVAC and have a specialist come out for me to put it back on.

You have 10k or so so depending on purchase/rehab cost it might be enough to have some skin in the game to make extra cash for your next deal.

If a Sailor can't pay the rent, the likely scenario is the chain of command will have them meet with the command financial specialist and look to get the Sailor living on board until they can get their act together. 

I payed the fee to become a pro here, to have some skin in the game.I think I will become a buy and hold investor, as I do not need cash flow to live. 

The New York Housing Association (MH trade group) will also be able to educate you to a certain extent on these issues and then suggest you need to retain either a specialist law firm or a consultancy like ours to help you.

Soaked to the skin, cold, wet rain.

A tax specialist can tell you more3) You have unlimited liability instead of limited.