Electric Meters: I doubt the even if the ADU is a separate structure they have a separate electric meter as they were mainly used for guests.

The legal status of the PM is that of the owners agent.

I also want to buy a couple of jeeps to rent out to guest, and I also want to buy a nice boat to take guest out on day cruises/snorkeling trips, but have the boat be nice enough that I could sleep in overnight in case I don’t wanna sleep in the small, separate living quarters at the property when being rented.

Doest it stay hot enough for guests use? 

Out of the tens of thousands of people who have claimed REPS and had a full time W2, only like 3 of them have successfully defended their status at the tax court.

@Kevin Sobilo I’ve done something similar with a restaurant where I was buying $50 gift certificates for $45 and then charged my B&B guests more.

Does anyone have recommendations for an STR on-call service (not full property management), which will handle basic guest communication during their stay and handle organizing repairs (i.e. calling a plumber, HVAC, etc. ... not actually doing repairs themselves)?

On a couple we have a handful of guests from booking.com, but we have one that sometimes gets filled 100% with guests from booking.com. 

Some of my larger homes are experiencing more guests than we can sleep. 

Once you figure out pricing for weekdays, you can also start offering those additional weeknights to your weekend guests for a discounted rate.