YES! Definitely do NOT use crankarm-bolt torque as an "adjustment". Use other things that are adjustable to fine-tune the bike, like FD limit-screws and cable-tension. You just have to search "loose crankarm" on here to see how common the problem of loosening crankarms is. A buggered crankarm may not be that big a deal, but certainly is more frustrating than shifting problems, especially if it falls off miles away from home.