Older buildings can be an issue, we had to put some spray foam around the heat pipe entries. 

I will check with my city officials on this issue as they've likely had experience with VRBO and ABB

The issue with someone porting into your area from someplace else is that they almost never have income when they move. 

 I certainly expect to pay for legal advice!  

You or contractor/handyman come out and diagnose issue and order part.

This is an older home that could potentially still have maintenance issues.

If your lease does not address guest stay lengths and it is legal to do so in your state might want to look for a new PM.

Also, told me money is not an issue but in the same breath asked if they could give less than 3 month's rent to move in (I had already explained the requirements). 

If the owner lives in California and their name is on the contract, then the owner may be required to show up in court for legal matters.

I’ve also managed units where on our renewal rate we did reduce the rent from the prior year, but for other reasons, such as the prior year of the tenant having a washer and dryer, and a major plumbing issue with the building, preventing us from offering it the following year so we did a reduction.