If a bolt calls for a specific Nm, and I go with the "really tight by hand, but not to the point where I might strip some threads" measurement, is this generally good enough. Am I at risk of my saddle coming off and the post lodging some place it wasn't intended, or my handle bars becoming undone on a particularly bumpy surface?

QR skewers are pretty much all tightened by hand, right? I can't imagine any worse part of a bike "loosening" during a ride.

What are others' opinions regarding the use (or non-use) of this tool?