I highly recommend this path if you have the social fortitude to live in areas that the rentals make the most sence, and you do not mind moving regularly.  

if it isn't fun you might as well just stick you the regular jobs!

If I am not mistaken, the regular forums are not for trying to sell your deals, please try the Marketplace: http://www.biggerpockets.com/forums/517-real-estate-marketplace

I have seen those go tumbling down the hill and the ones next door with regular foundations were virtually unharmed. 

All of this to say, unless the agent has a proven track record for renting similar places or a network of potential customers (read: international companies regularly relocating workers), I wouldn't bother with them.

Regular repairs and maintenance are not included in the tax basis of the home.

Check crime and boarded properties on that block and see how many are being advertised as vacant and monitor for few weeks if those vacancies fill up or not.

Further, once someone became serious about the purchase it would be disclosed by necesity of the process.The first buyer to offer on the property, negotiates with the lender and this initial offer proceeds much as regular transaction what with the ability to have due diligence clauses such as inspection, financing etc...

How is turnkey different than a regular 2 unit one would find in MLS?

@Wayne Brooks What would you use as regular protocol to search for "unrecorded" liens that you can track down but may not necessarily be in public record like you alluded to above?