Rent to own has few if any safeguards for the renter....because he does not have title.

A really helpful tool to choose your optimal amount of leverage is a sensitivity analysis, which will weigh how much leverage you use (0%, 10%... 90%) relative to adjusting 1 other item at a time, such as appreciation or rent growth rate etc...  

For my landlords out there- what are some of your tenant horror stories and what did you learn from them so you could put safe guards into place to avoid the same disaster with further tenants?

Cleanings are a sensitive topic of STRs.

You'r paying pretty much the same thing and getting less representation and you're losing some safeguards as to an agent's duty and their liability.

and you have little built in equity, leaving you very sensitive to market risk.  

While there are ways of safeguarding against pullbacks in the market such as longer lease terms, the risk of a pullback is always relevant.

Be careful of incurring liabilities in a sensitive transaction.

Timing being of the essence or not, you still have to be sensitive and make sure that you're not coming in looking like an opportunistic vulture.

Keep in mind the answers to your questions are highly subjective and market-sensitive (Metro Atlanta, for me).