erbuscap, I don't think you have to worry.... no bending over for the medical in China (yet?)
Wyomingpilot don't scare the newcomers. Last time I checked nobody (from the CAAC) looked under my underwear for anything. Maybe when the contracts pay 30k/month they might get someone to accept it...
That said, if there was something serious done, they WILL probably find out from all the other exams they will put you through. So do declare it if you don't want to worry about it. Scars and tattoos are not what the average American-European should worry about anyway.
Besides, I think it is funny like you said, and I am sure many China veterans will drop by and share their experience about the "strip down" question, so rovespier will have something to read in the next few days.
Wyomingpilot is right. Try to stay on top of it, but don't try to understand their ways... I am not sure if it was USMCProbe or another forum member that said "F*** it, this is China..." but he was right. Most of the times makes no sense, but thats the way it is. You have to accept it or leave (or not try it at all)
3 months for background checks.... thats only because of incompetence and chinese procedures. Try 6 months line training for senior Captains on the same type! But of course its the training pay that makes sense, you still fly the same hours for them.
Good luck