What is unclear to me is does the material participation need to be on each STR property or in my real estate businesses as a whole?

All maintenance is also on them.

I know its mean to say that people who do their own contracts get what they deserve, but you must know that if you are paying a couple hundred thousand dollars for something it just might have been worth spending $600 on a lawyer to do a proper contract for you.

@Stuart Udis has hit the nail on the head.  

Work at establishing in-person relationships that will serve you well over time, not just one-and-done.

Quote from @Andrew Steffens: I think most people here will caution you on these courses. 

I only have one right now, so the monthly subscription is a bit hefty for me.

First time on this forum, and just introduced through two books I just read by David Greene and Brandon Turner.  

That is not going to be a good situation in 5-10 years when there are so many rentals in one neighborhood. 

I've actually pulled the plug on investing to focus on our general contracting business because investing was more of a distraction.