I agree with everything you've said except for the bit about puzzles -- I've never found any correlation between the results from burn-the-ropes/odd-shaped manhole cover-type questions and strong programming skills. I've had at least one candidate who did superbly on the puzzlers (had clearly not seen them before)- best performance we'd seen-and could not program his way out of a wet paper bag. We stopped the puzzlers shortly thereafter. Brain teasers are a waste of time.