All that to say, I'm not sure when they will want to cash in and sell the lot due to the appreciation the subdivision has provided.

This is a physical asset, not paper, and it's providing consistent income.Albeit for your not understanding tax laws and depreciation, I'm wondering why there's a question as to what you should keep.You understand capital gains, but I'm pretty sure you're not familiar with depreciation and loan paydown.

but they don't provide current rent, value, what they have capital wise, etc. 

The CFPB made it very clear recently that all of the same consumer protections apply to them: CFPB Takes Action to Stop Contract-for-Deed Investors from Setting Borrowers Up to Fail There are very few if any places these days where you're just going to easily toss a borrower out with a land contract.

Provide them proof of your ability to find, fix, flip (or whatever strategy you plan to use), and then start with small amounts of their money.

Is it right that short term rentals are considered as licensing the property for use (similar to a hotel) and not a lease for a long term rental and therefore do not require a brokerage license to provide management services that include price adjustments? 

If it is someone you know you can give them a straight return as if its a loan - can provide a lower interest rate to provide upside - it really depends on the lender and what are they concerned with and what is their risk profile. 

My latest blog - linked here  "UNDERSTANDING FLORIDA'S EVICTION PROCESS AND LAWS"  provides a comprehensive guide to understanding the legal requirements, timelines, and steps involved with Evictions in Florida.

Our job is to provide you assistance. 

And the guests are able to stay in a better property than a typical hotel room can provide.