Municipal restrictions and fees, capex investment needs, and sky high water/sewer and trash expenses are killing my cash flow.

One of the challenges I can already see is understanding permitting and zoning restrictions for STRs depending on the market. 

Another thing I would double check is the zoning and/or any restrictions that may effect the lot as some don't allow manufactured homes.

The main restriction on using the Section 121 exclusion is the ownership and use test.

Are there STR restrictions in those areas ?

I've personally transacted on a house +ADU + JADU that was rented to three separate tenants.If I am taking the risk of breaking a deed restriction, I expect the associated discount. 

Do you know of any in Scottsdale without minimum rental restrictions?

After 3 or 4 years of the county fighting our neighbor, they passed a very restrictive ordinance that affected both the neighbors property AND our property.  

No slab houses, age restriction too i.e. expectation to be paid in full before retirement.

Take a look at your listing in incognito mode, you may find it has now been removed or made hard to find.Isn't there a way have your calendar open but to restrict your check in days to the first 2 weeks of May, or whatever you want?