I think it's wrong to say that you can judge somebody by their handshake. In fact I'd go so far as to say that's bullshit, although I hope you're not too offended.. People are just too complex for that, dude..

Anyway nah I don't really think firm handshakes are that important, but I have a couple of friends who have the most weak-ass handshakes in the world, and it usually irritates me.