.#1:  Rules of thumb will eliminate good deals as well as bad. 

If they are trying to do that, it is only a matter of time before they eliminate STRs all together.

.- Plan: eliminate AMT - Alternative Minimum Tax.

So I gravitate toward things that are well understood, proven, time tested, tie up all details in a nice neat little package, and eliminate as many variables as possible. 

Name one product that completely eliminates lead generation costs, and efforts, where the leads chase you instead of you chasing them?

This eliminates payments The point is that the HELOC (or other credit line) itself does not figure into the mortgage acceleration scenario at all - it could just as easily be a revolving personal / unsecured credit line.

Purchase concerns, I only know Roku, but the few apps(channels) that have this on Roku have a purchase restriction option you can turn on to eliminate this problem. 

I edge my odds by not allowing 1) last minute check-ins (must be at least 2 days in advance) 2) No 1 night stays (eliminates partiers) 3) Must have previous good reviews.These will vette 99% of your guests adequately....

Eliminate debt, establish a budget, and save.

As soon as interest rates or your personal situation are favorable you can then refinance at any time and eliminate the hard money lender.