The only draw back I have is that AMEX isn't accepted everywhere but otherwise we like our AMEX Blue Business Card.

There is growing industry and plenty of tenants looking for a place to stay. 

He was happy to allow me to rent out nightly because it actually helps keep his property in better shape than a long term renter (having a cleaner in there every turnover, short stay guests always let you know when something isn't working, etc) but didn't want to hassle with worrying about a percentage of income/management, etc.

Insurance is paying for the stay.

In theory if I stay "retired" from W2, for CY25, my spouse will likely work half the year and call it. 

Let’s just say this house taught me the importance of staying calm when your plumber says, We’ve got a problem, and your electrician just stops answering calls...

They'll moisture meter everything affected to see if it needs to be removed or can stay.

Stay at it for 2 or 3 years and you will have your down payment 

Usually if it’s a revaluation where the whole town goes up in value you see the tax rate decrease and taxes stay the same or go up a little like yours did.

You could live in one unit and rent out the others to offset your mortgage, staying within your $4,500/month affordability limit.