I told the couple that I got an offer for $1,700 but wanted to ultimately rent to them but need the income.

If the market is strong, holding could lead to future gains, especially with depreciation deductions offsetting rental income.

They are a great tool becuase some lenders use AirDNA to qualifiy rental income if the property is not actively an AirBNB.

I don’t have a loan on the property and hold it cash, but, if I sell it would lend the profits as hard money and earn 10%+. 

You might have to give up some income from the rentals but it gets you ownership of the park and time to fund long term financing.  

•Incoming Market Changes & Local News: Keep an eye on city regulations, new developments, and economic shifts that could impact STR demand.

I think the OP is talking about property tax not income tax ??

Speak to lenders, have a nice package together: they will want an SREO, your background, your assets/ income etc, they will want your "business plan", your underwriting, your capex breakdown line by line. 

I’d suggest focusing on securing solid DSCR loans—like those from thelender.com, which lends up to 80% LTV, considers STR income, and operates as a direct lender.

You should be able to use departing residence income from the market rent when qualifying for a new primary purchase.