I feel like I have the theory and the mechanics down for house flipping thing.

It's nearly impossible to see every difficulty that may present itself... anything from Mechanical failures, Roof problems, Electrical or Plumbing problems, Structural issues, etc.Most importantly... know your end game.

We had to fire a contractor, who then put a mechanics lien against the property.   

It goes on with every business, even the auto industry uses Wholesalers, if I were are realtor, I wouldn't fight it, it's a loosing battle, I'd try to benefit from it, by becoming a broker, then I'd rent a desk to you and have you wholesale for me.

It is possible that a contractor will put a mechanics lien on the property prior to closing.

Same scenario as above except that the principal on the first is $125k.I have a feeling that the answer to the next question can be inferred from the answer to the above question, but what happens if I own the second (say I bought a mechanics lien/judgement from someone) and the first is $50k and the lien I bought is worth $10k and the property is worth $150k.  

They still have phone books start there.I have come across a couple auto dialers online just do a Google search and your research.  

When looking for any information regarding your credit this link for www.myfico.com usually is the best place to start.Here is what Myfico says about credit inquiries...Looking for a mortgage, auto or student loan may cause multiple lenders to request your credit report, even though you are only looking for one loan.

I have gone to public wifi hot spots and done a totally new ad with new EVERYTHING, and still have had ads auto flagged.

Doesn't seem like your analysis has any account of all the repairs needed to make rent ready.Sheetrock:  $25 to hang a sheet, $25 to skim/patch a sheet, plus the cost of each sheet.Paint: about $250 a room depending on how expensive you go with paint.Flooring: $2 - $8 a sqft depending what you end up doing Get all the mechanicals checked out as well.