WRT Chalk & climbing, propensity to sweaty hands differs from person to person, but for both myself and my climbing partner, need for chalk is almost all mental. When I've got a cool head and smooth moves, my hands are dry as a bone. When I'm freaking out on lead, my hands get progressively more slippery...

FWIW chalk improves the friction coefficient of your hands, and seems to reduce friction damage to the skin, so I try to use it anyway.