Would you still use your friend as your GC and just pay him his regular rate (and would they be happy about the new arrangement)?

I don't know but I have plenty of Canadian and American friends and acquaintances who travel (regularly) to Mexico and the Dominican Republic but I don't actually know anybody who has vacation in Puerto Rico (unless they haven't told me of course).As can be expected, the most profitable form of real estate investment in the region is short-term rentals.

And he knows who's working regularly, who's only off-and-on, who's going through troubles, who needs extra work.

Quote from @Will Ghidotti: Hi Amby, I am a real estate attorney and handle this issue regularly.

Even updating the listing regularly so the OTA knows there's someone actually running the place behind the listing.

Versus in the new era, where I think the buyer pays similar to what they are paying, the buyer's agent takes less, and the seller ends up keeping more.

They are responsible for the upkeep on the house and we are responsible for the land and underground utilities.

I put in my time in finding the deal, financing half of the down payments, finding tenets for the property and general upkeep and maintenance.

There's also regular inspections of both the living conditions and conditions of the home, and I've known some LLs in my area to fail for really stupid things (like a broken screen that the tenants must have broke), and if you fail no money until you pass. 

You'll also want to ensure you have a good property manager to look after the upkeep of the property if you are not there to notice anything deteriorating or which may need attention.Creating an LLC in California could cost you a minimum tax of $800 every year.