Since there is a co-owner, you would have to purchase the property and it is really hard (if not impossible) to pull a HELOC as the basis for the purchase (since it is not your primary residence). 

It is much easier to find HELOCS for your primary residence, but some lenders will do a HELOC on a investment property as well 

I figure if the equity we have cash flows better than similar equity in a single family residence in Utah would, then we should consider this AITD as a serious option.

None of these communities will be changing to residential neighborhoods, although a couple do have residential 'sides' that full time residents live in and can not be rented short term.Two of the big communities that you will have some issues with self managing are Reunion and Margaritaville.

I would have thought San Francisco is oversaturated with STRs, but that's what several people are doing, buying primary residence and house-hacking a separate unit on AirBnb.

I agree with what others above said, that having a reliable, honest and knowledgeable team is the most important thing...more so than perhaps the location. 

We recently relocated from our primary residence to a rental property ourselves (we recently welcomed a baby, and our house no longer accommodated our evolving needs).

I don't think being a long distance landlord is as easy as some tout but full disclosure I've stayed with 80 miles of my primary residences. 

They eventually sold their business to another company and things were fine after that.All the others were easy.If you are going to switch, you might want to try that after a resident moves out.  

Investment Info:Single-family residence buy & hold investment.