I then check social media, google, etc for information on them before deciding whether to waste my time showing them the property. 

If you think it will be minimal then I would charge less.  

Total waste of time and effort... move on ....

If you do what @Brian Gibbons suggested you will minimize if not eliminate any loss on your part.

Usually because the seller wants cash for the house ASAP and they do not want to waste time listing it with a realtor or they are too uneducated to list it with a realtor.

They make you excited and they waste so much time because most are expecting a quick paycheck.  

It just never seemed like rent in Louisville was very high compared to property values over the years as I've minimally been looking around. 

On a Oahu $600,000 gets you a single family house or condo with 1 tenant, minimal property upkeep, aggressive appreciation gain, consistent renter pool (military/DoD contractors).

You might say that's a worst case scenario, but you have to think these things out if you're going to write your own legal documents.I get that you want to encourage the tenants to keep your property nice and try to minimize your own repair costs, but unfortunately you just can't make the tenants responsible for everything. 

If the siding is asbestos you can cover with minimal costs but if you remove then you are talking about possibly needing a specialized company coming in to remedy it.