In fact, for investors that are stubborn and insist on doing so, I tell them to only consider it if  they are breakeven on their monthly cash flow with the property AND they plan to hold for 20+ years.  

You are on the clock.If you are insistent on Airbnb for the property I would focus efforts on sourcing local private funds than go mainline banks. 10 years may be tough, but 5 years probably should be ok.

They insisted and showed up at our house one night at 9pm. 

If they insist on disputing a charge, I ask them to write their dispute and provide me with any supporting evidence to back their claim.

If they insist on just side soil samples, then I wouldn't feel comfortable w/ just that.

Can I insist on a co-signer since they won't qualify by the time they move in? 

We disclosed to our lender we plan to use house as an STR, but our lender insists on 15%. 

Let them know you’ll pay for the work, the insurance liability would be yours if it went wrong (if they were smart they would insist on this in writing) and maybe offer an increase in your condo fee if the condo fees pay the water bill.They still might not do it and it’s very reasonable of them to refuse if this is laid out in the docs.

The most successful landlord I know in town insists that his properties always look a little nicer than comparable rentals in the area.

Members of the chamber were insistent that diversification of industry was the solution, so they catered to a variety of revenue sources.