I’ve been looking into Vintory's CRM since it’s specifically designed for the STR industry, but I’m also considering HubSpot for broader capabilities (and because it's free for up to 2 users).

Ken’s questions should be foremost in considering the purchase.  

@Aaron Zimmerman Good point about structure set up and determining cost bases.

Most lenders group all hard credit pulls within the same 60-90 day and consider it "one pull".

Our standard language states:In the event that Tenants decide they no longer want to live together, ___________ will be considered the primary Tenant to make decisions about modifying or terminating tenancy.

To make taxes easier we set up a business checking account and had all the rent paid into that account and all the expenses paid out of that account.

Consider experts like @Brian Eastman or @Bernard Reisz for help.

As long as the city considers your property a true SF, you shouldn't have any issues getting this permitted (in theory, yet to see how some municipalities will handle this law).

We are seriously considering  rent to retirement properties given the relative passive nature.

Consider having a tool like PropStream or Foreclosure Radar.