Also make sure you get his security deposit as you will need to return it to him in full when he moves out as you have no idea what the condition of the home was when he moved in (and let's face it after 24 years most damage can be considered normal wear and tear). 

BRRRR, flips, long-term buy and holds, high cash flow, good potential appreciation in the right areas, mid-term rentals (many traveling nurses come here because of the Cleveland Clinic), Air Bnbs, etc.

The locks that I use also specify to use Alkaline because Lithium can damage the electronics in the lock. 

As long as you don't argue with them or make them mad, you should not experience more than the usual brain damage of getting permits.

The property has been vacant for awhile, and any searches I do brings me back to the damaged/vacant property and no additional info. 

If the oil runs out and results in damage to the system, the tenant will pay for the repair.I also recommend you be clear about this in your written lease for future renters.If there are repeated violations, terminate their lease and start with a new renter.

I'm a flight test engineer by day, currently stationed at Eglin Air Force Base, FL (just across the bay from Destin). 

Water, air, sewage?

I haven't had any problems at higher temperatures, but the lock itself is inside an air conditioned property.

For example, if a family is displaced due to extensive water damage that will take a few months to repair, the insurance company will then look to find temporary housing for their customer/displaced family.