STR management is 20-25% (I would recommend self managing or getting a VA), since income is higher you could probably get away with 5% for maintenance / cap ex but remember you need to cover utilities and cleaning for these units which drives up costs.

Umbrella Policies are good, but they are not an asset protection tool, they only cover litigation/damages after you’re already in litigation or found personally liable.

With the situation you're going through, your first thought was likely "I'll raise the rents to cover this." 

Buying & selling it as land, no development.Perhaps what I have covers all the bases I am looking for. 

Taking a small cut to cover transaction costs and operational expenses is standard in platforms facilitating financial agreements.

This would make a great co-hosting opportunity without worrying about making enough to cover rent.

I've had clients rent by the room short and midterm and covered their entire mortgage.

If you have the means to cover debt, you can avoid the accounts being liquidated.   

I do not know much about San Antonio market so will cover pros/cons of San DiegoCons- price of entry.  

I also want to clarify that I do still keep a decent amount of cash - just not enough to cover every single property roof at the same time if that ever happened for some reason.