RE: Wavers?
If someone wants to sue you there is nothing to stop them. At that point it becomes your word against theirs anyway. If a person can qualify utilizing the basic requirments as set up in AMA, that is all all that is needed in my opinion, moreover that is all the lawyers would look at anyway.
Bottom line, if someone performs the requirments but you are still not comfortable with that person then don't sign it. I would never sign off on someone that had the skill but not the maturity to operate a jet safely. Still, its not rocket science and there is no need to add additional burdens to someone trying to get a waiver. At some point and time you have to simply trust that they will do the right thing. If you are worried about getting sued then don't sign one at all. There is no guarantee that it won't happen, even if you are 100% certain and sure of the person you are helping to get a waiver.
Andy