You can get a signed agreement and if they fail to perfom you at least can feel like you are a decent human  being and gave them a shot. 

This may sound dumb but i am trying to gain as much info about REI as humanly possible to let the different avenues call to me.

Then you get to be happy now, and when you start to feel your body getting tired of working a regular schedule, by then you'll have a nice investment portfolio.

I think scaling is more of a human resources thing.

It's human intelligence, as with an intelligence agency, nothing to do with IQ.Select buildings that are basically in your price range.

Have collected rentals over my working life and managed them myself( since retiring 20+ years ago), and am finding it more and more difficult to keep up with the maintenance, management, and tenant selection process as the body is not as agile as it once was and either is my patience. 

Then, I give put the form in the property owner's face, tell him if he sells his property the conventional way through a broker he will have to pay a 6% commission and I get a verbal acknowledgement, positive body language and I ask the property owner to write the amount of the form.

An HOA is just one more governing body that can limit your ability to run your business they way you want.

It would require a LOT of knowledge to do right and humanely.

For example, “Excessive noise is any noise that is under human control and of such a nature as to unreasonably interfere with the peace, comfort and convenience of any person.”.Every city and county have their own noise ordinances.