I don't know where you Crossfit but I live in Florida - it's hot and humid here and sweaty hands are an issue when lifting. I don't use a lot of chalk, only if I'm doing heavy deadlifts or cleans etc but sometimes it is necessary. There will always be people who abuse it though, often I see chalk all over the place in the gym - to me that is ridiculous. As far as tearing callouses, if you use a callous remover (razorblade with a handle) and keep them shaved down you won't tear them.

I changed my grip a la Mark Rippetoe and haven't had any problems with ripping or tearing. I still have nicely built up calluses but nothing thick that I need to shave down. I really keep an eye on them so there's no injury to my hands, the barbell gets enough of my DNA from Dead Lifts.

I lift with guys that are going uber heavy and have never seen them utilize chalk.. and then some that are definitely lighter lifters who go crazypants with it. If, and when, I use chalk it's always just a light dusting and has only been on those super sweltering summer mornings so my grip stays firm, usually during KB's, instead of the Scarface type levels that some of the guys use all the time.

In my opinion, if you aren't lifting the weight from the ground, whether deadlift, clean, snatch, etc., chalk is unnecessary. I watched a guy do front squats with chalk the other day, picking the bar up from a chest-level rack and using only two fingers for support. Seriously?

This is a good question, i often question why i chalk so much. I havent had any problems since i started using though. Used to rip my hands from kbs and pullups but i also tape to prevent on pullup or loose grip exercises. Little bit of placebo little bit of help? Confidence powers most of these excersises

Chalk is nr. 1 safety measure when doing heavy snatches. I use it when I have the possibility. Try to have a barbell with more than your body weight in a deep catch with sweat hands and you'll understand what I mean.

We used to be chalk feens at our box and the rips on all of our hands were insane! We have totally scaled back on chalk use and though at times we still do rip, it is nothing compared to what it was when we would overuse the chalk. A friend of mine had rips in the strangest places (like close to the thumb) and it put him out for a week the rips were do bad. Don't get me wrong, we still use it, but SPARINGLY!