It's not the Steam version, what will happen if I try to sell my PC copy? Will I need to give away my gamesas account away as well?

No. The new player can create his/her (female FPS player WTF?) new profile. And CD key is not binded to profile, but two player with the same CD key can't play at the same time.

Thanks for your answer! So if I never want to play this game again, I can sell it and it will work for the other guy just fine on his own newly-created account? By the way, did you try this yourself?