I also run a local meetup that I recommend you attend to meet like-minded people:Good luck and welcome to the community. 

Maybe that is not the case today, but I have always favored tanked WHs, especially on my own homes.Most people may not care about this, but.....in the event of a disaster, if you have a tanked WH, you will have 40-50 gal of stored accessible water at your disposal.

Attend local meet ups, get on wholesalers lists, tell everyone what you're looking for. 

They quoted an umbrella policy for $200 extra, which is very reasonable.From my limited understanding of insurance policies, if I have the second-home policy with home sharing endorsement (personal liability $1M) plus an umbrella for $2M, then I should have about the same coverage I get from Proper, even in the unlikely event of an off-premise liability lawsuit. 

Subscribing to local real estate newsletters or attending local market meetups can also give you a better feel for what's happening in your specific area.

I just attended the Bigger Pockets Conference and I discovered there were many books you can obtain through the Bigger Pockets website that might help you in your journey.

SPI advisory has the best pitchbook I've ever seen, Elevate is local business that I actually attend one of their event.

For the moment let's leave out what I paid for the land, because it will vary and in any event it is easy to subtract that amount at the end. 

According to Airbnb's Major Disruptive Events Policy, you should be able to cancel without any fees to you or the guest. 

Unfortunately most investors focus their time and resources on preparing for the liability event rather than proactively operating their businesses in a manner that prevents the liability event from occurring.