your the exception not the rule.. 

I've considered all costs except I'm not sure I understand, "contingencies for cost overruns".

They are generally conceived as bad, with exceptions to people having nightmares, but most of that likely has to do with bad screening. 

All other expenses that were before you had the property ready for rent would be considered start-up costs and would have to be amortized over 15 years, but there is an exception that would allow you to deduct up to $5,000 in the first year under IRC 195(b).

One that has strict STR permitting with exceptions for owner occupants would be a bonus.

I do all of the work except for contract review by broker and they pay for the pm software and overhead of having a physical location for the brokerage (although rents collected and owner payments are all done online).

If you act as a consumer and unless any of the legal exceptions apply, you have rights to cancel the Subscription Listing Fees during the cooling off period.

I feel the value of this condo is at its peak considering the market.Are there any legal exceptions for the 121 home sales exclusion if I buy another primary residence shortly after the sale to avoid tax?

  - They can be exclusive with named exceptions (e.g. "... pay you a commission for any purchase I make unless the property is one of these specific properties I'm already aware of or for properties brought to me my someone on a specific list of other agents I'm already working with)

This is an exception under all insurance policies so the next question is even if successful with a claim how confident are you to ever collect from this seller without insurance cooperation?