They will go after the original user of the chip for letting it go, not the OP. Not a big deal. If it's a pre-release chip that shows up on Ebay, being sold by a tester withing the 'loop', well then Intel might do something.
Not a worry.
Pre retail chips might be good, might be bad. You won't know till you try it. It's still in the testing phase.
And yes, people do buy these chips. I bought an i7 965 DO stepping (no such retail chip) for way under 1/2 of what a new i7 965 C0 would cost, saved over $700. The chip has worked fine for me.