However in my normal friend, family and colleague circle of a few hundred people that I interact with somewhat regularly, I can count on 1 hand the number of people who I know have a rental, who all have a tiny house/ADU setup on their primary residence. 

If I was to give you homework from our interactions on this thread it would be to go analyze 100 houses using the BP calculator for your target market.

Again, the BiggerPockets store has some books for this or you can learn by watching podcasts, reading blogs, and interacting on the forum.

It makes sense to have an Operating Company for all interactions as well as a Holding Company to own the properties.

Again, the BiggerPockets store has some books for this or you can learn by watching podcasts, reading blogs, and interacting on the forum.

While I would normally agree @Tyler Solomon, this isn't something the guests interact with.

Grandma is the one I interact with. 

You want to make sure that you try your best to make sure that every interaction you have ends either neutral or better and if anything does start going poorly, try your best to rectify the situation before the interaction ends so they don't leave with a bad taste in their mouth (or at least not as bad of a taste).While a lot of this stuff may seem like common sense, I see lots of my coworkers failing to do these things and it shows in their numbers.

The reason for using both LLCs is to separate the liability of interacting from the liability of owning property.

The new Broker license has the same privileges of the previous Salesperson license category, but requires additional education to include 90 hours of pre-license education, 15 of which must be interactive (classroom or webinar) and 30 hours of post-license education.