I had several clients who experienced problems with fly-by-night contractors who set up shop because the demand was so high they could inflate prices for unimpressive work.

It may be somewhat arbitrary because the value is in the land under it.If you price it properly and there are builders in the area, it will sell even on the MLS. 

Properly screen her as usual and then add her as another occupant but he's the financially responsible tenant.

Any Ideas on how to properly follow up with old contacts.

Not to scary, meaning I don't feel threatened if I have to go there at night.

I will stay at the airbnb at least once (probably more) to come behind and check that everything was properly taken care of, but I can't make that trip constantly.

if you are near the end of the lease for the tenant you can list it with seller notes saying currently occupied and will be delivered vacant by end of escrow and make sure to give the proper notice to the tenant that you will not be renewing it

Our turn is weekly during the summer season (Vacation rental) and a minimum of 2 nights "Out" of season so we clean it a lot, and each couple alternates every-other turn. 

I found a off-market deal about 2 months ago, and I was about to close the deal, but apparently the owner has some tax problems.They owe 6k at the county and from what he said " there was an issue where their payments were not being properly applied to their account for several months and they can't even make anymore payments until the company tracks down the payments they already made".

A proper lender will be happy to oblige.