What would be safe neighbourhoods, reasonably priced and investor/ rental friendly.

The one thing I can say is a safe bet is getting long BTC. 

Simply safe

In addition, as others suggest, guest damage insurance such as proper or safely would be good, for those bookings off Airbnb/vrbo where guest damage coverage isn’t available. 

While we are not truly concerned with making it someones dream home, we do want it to be smooth/safe with a modest level of eye appeal and without a massive time or money investment.

For argument's sake, and to keep the math simple, let's say you have $1 Million in ETF's or some other safe-ish, well-diversified assets.Step 1:  Take out an SBLOC (Security backed line of credit) on said portfolio. 

I can't speak to the return thresholds for development but it's safe to assume it's higher given the larger risk profile.That being said, it doesn't hurt to give it a try as you never know where those new relationships will take you.

I think it's a very safe bet to see the inverse true, and then when you classify demand out(the one's who are interested but cannot qualify) it'll get even wider.3.

There is a hospital (First Health Moore Regional) near my location; I would think traveling nurses would want somewhere safe, quiet, and not too far away (easy drive) from the hospital they're working at.  

It's definitely a nice and safe area, especially coming from the Bay.