@Joel O.Based on your OP, assuming even the 75% income credit... it would appear that your rentals are either losing too much money (based on standard underwriting) or you are shielding too much income in your tax filing.If your 75% rental credit, for that specific rental you have is sufficient to cover the debt and operating costs, then that should technically not affect your DTI a bit.

To build something that really is a retirement/ life insurance replacement - it needs to be self sufficient.

In the location where I invest, obtaining a standard rental license is sufficient for rentals lasting over 30 days, and this option is generally more affordable and less complicated compared to obtaining a short-term rental license.

The issue will be the FHA self sufficiency test. 

Small passive income that is sufficient by reducing consumption and spending.

My understanding is that if you have a regular job, it's almost impossible to sufficiently claim REPS.  

Your only option then is FHA which you will need to basically find a 2 unit under $500k because the self sufficiency test is very hard to pass for 3 or 4 units. 

If you own the land all the way to the lake, I would expect some basic signs, good insurance and perhaps a lifesaver on the shore would be sufficient. 

Your basic insurance policy with $300,000 in liability coverage should be sufficient in 99.999% of all lawsuits.5.

While we live in the area, our goal is to make these STRs as self-sufficient as possible so that 1) the cash flow they generate becomes increasingly passive, and 2) we feel confident investing in STRs out of state, which we’d like to do in the near future.