After you address the leak it might be worth looking at additional venting or conditioning the crawlspace with a duct from the air system.

He said he wants to move out (6 months left on lease yet) So I told him I would serve him a 14 day notice to vacate, and if he was out by then, I wouldn't file an eviction and we could call it a wash.I'm not concerned about missing 1 months rent, especially since the kid looked like a deadbeat anyways.

The concern is that there may be some technicalities within the PM side that might prevent us from doing this, so that’s where I need your help!

As a general rule, you want to use an S-corporation.While liability concerns are an issue, that is not the main reason I am saying to use an S-corporation. 

We looked the house up on the county website and found that the owner is listed as a trust, different mailing address, and that the taxes have not been paid for the last 2 years.

Of course I have his name and address (it's actually a business address) from the tax record and, of course, I've sent him mail.

My concern is covering the turnover time, and I am trying to figure out how I can get that covered in the new short-term lease extension. 

Think of all the things that could go wrong and see if the lease addresses them: unauthorized pets or tenants, early termination, security deposit, lease violations, late rent, eviction, lawn maintenance, parking, etc.5.

Several more questions later I was ask for the address of the investment property. 

Unless a State Administrator tells you different as far as state is concerned about its laws I would do it per the state law and give them 60 days notice on their vacating along with a month-to-month lease or do the "cash for keys" deal a try.