Yeah, I hear ya' about the waiver wire. That's actually why I don't draft a backup defense. If I have a stud defense, then I'm probably gonna use them every week - so I don't need a backup. But if they're mediocre and I'll have to swap out based on matchups, then they'd probably be safe to drop to the waiver wire anyway, since no one else should be racing for them and I can just pick a defense off the wire each week. To each their own though - tomato, tomahto.
Out of curiosity, where did guys like Cutler, Romo, Palmer, McNabb, Ryan, etc. go in the draft? Usually if all the big dogs get drafted ahead of me (Brees, Brady, Rodgers, Manning, etc.) then I'll just say "screw it" and load up on more RB/WRs. After those guys, the next 5-10 QB's are pretty indistinguishable, and you can usually wait a few more rounds before that next tier starts to get exhausted. Basically, instead of using a Round 5 pick on a Tier 2 QB, I can grab another decent RB in Round 5 and then wait for Round 8 to get a QB, and still get a Tier 2 QB.
Your mileage may vary.

It depends a lot on the guys you're drafing with. In my work league, we had a run of like 8 QBs in the 2nd-3rd round. All the big guys got taken. So I said screw it and loaded up on more RB/WRs while everyone else was wasting picks on QBs. I waited about 4 more rounds and was still able to grab Romo.
I love fantasy football strategy discussions.