An odd thing that seems to happen with me is when I set the rent near the top of the market, I at first thought it would weed out bad tenants and leave those in good financial shape. 

I made a success of my computer biz, am in decent physical, financial shape, and hopefully reasonably savvy.

It is not unusual for some repair to the roof deck to be needed but unless the roof was in really bad shape it does not usually need to be replaced.

I noticed a couple of years ago that a house in a certain town that was in horrible shape had some official notice posted on the front door.

I have not done one yet (shame on me) but feel I have a good grasp...If a tenant buyer is in good, upwardly mobile financial situation (ex they bought another home and this is the second one... they didn't need the cash out to buy house 2) then Lease Option is a good idea.If a tenant buyer is in bad shape (your buyer, those about to be forclosed on, bad credit without a valid reason like medical bille, etc, etc) you need to do a subject to (get the deed) so you can be in control of the property fully and not relying on them to pay (as they have shown they are unable)I would never allow the original owner to stay and make you payments on "their" house.

I have noticed the disturbing trend, however, that my credit score has been slowly but steadily declining over the last year.

Look at the diet trends: Fats are bad, fats are good; carbs are bad, carbs are good.

It was half vacant and in bad shape.  

Is the foundation in good shape or does it require a complete replacement?  

The house is in good shape.