Bad credit, no savings, a low-paying W-2 job, etc.

Perhaps you can send him an email that simply states that if he does not return your keys, you will have no choice but to file a police report in two days, which would be a hassle for both of you.

The money got tied up in several bad investments and some might just have been partied away.

I don't think you can fix thisPlease note that the Auction site counter bids themselves on behalf of the owner to bring price closer to reserve.I am sometime bid on a property for 2-3 months until price is within my desirable rangeDon't buy a bad deal just because you cant a good deal

Sometimes we have to be cold hearted, although we might feel bad for tenants, previous owners (in this case), etc.

If you have the mindset that you are there to serve your tenant (customer), then you will be much more successful in my opinion (of course in business, sometimes you need to fire bad customers!)

I became interested in part because my family was in a bad car accident where 2 kids street racing hit us and almost killed the 4 of us including my 5 month old son and 3 year old daughter. 

Very few have tha cajones to go in when the market is bad like in 2009. 

it doesn't seem bad, but it does seem inconsistent.11K for a tiny roof, seems very high800 for a tree, way too low!

-Ask him why he's selling (this will likely bring up a pain point for the seller, which is good for a sale: bad property management, bad tenant experience, doesn't have time, no longer lives in the area so he/she can't properly run the property, etc.)