I'm also seeing lots of homes for sale that were used as Airbnbs, so I'm wondering if that along with these numbers may indicate it's an overly saturated market, and if these are signs that maybe I should keep searching for a stronger market, or just a property that cash flows given the average annual revenue?

The easiest is doing a search for REI Meetups.

And lastly, I search FunishedFinder listings nearby, find comparable properties, and track the listed rent for a few months (does it increase, decrease?).

You can put the number into a search engine and sometimes it will tell you if it's a solicitation.

Here are a few suggestions on how you can maximize the wealth of information available: Check out the blogs and podcasts, or take advantage of the search feature (magnifying glass).

To provide our buyers the greatest probability for success, we cast a wide net to evaluate ALL vacation rental prospects and narrow it down to the handful that meet the search criteria. 

You can also search for local FB groups that specialize in longer term stays.

- Will they search for off-market properties for you?

Start by going to www.narpm.org to search their directory of managers.

You can also use the search feature (magnifying glass in upper-right) to look at previous conversations.