Anyone lost on both mixes just remember this simple code: A + B + P = Crystal and A + A + D = Boom! (Add Boom to Bomb and then stick it somewhere *normally* un-advisable to get 100% Decontamination.)
Tip for everyone: BEAT THE GAMBLER! You get a real fun surprise when you do. And by beat, I mean clean him out completely. (He also doesn't come back after that)
To win in Relaxed, try following Naruto98001's advice except start as a Parasite. And if you get lucky and snag the "Biohazard" trait, make full use of it!