So I'm pretty set on where I'm headed to school in the fall but I have two schools that have invited me to admitted student events ... I have yet to withdraw from these schools.
By "pretty set", does that mean you are still waffling or does that mean you have already made your decision? I would not say you're an a$$hole for snagging some chicken fingers and fruit juice to recoup your application and LSDAS fees (and wasted seat deposit?). However, if you have known with certainty for some time that you're attending another school, then you ARE being an a$$hole for sitting on a spot out of ego/laziness/whatever instead of withdrawing once you made your decision.
Alot of folks on LSD don't believe in withdrawals at all, and just take the they'll-figure-it-out-when-I-don't-send-a-seat-deposit-or-show-up-in-the-Fall tact... either out of ego, laziness, or a misguided notion of "getting back at the system" for causing them so much stress over the past year(s). Telling someone to withdraw your app from a school they know they won't attend is probably a minority position here. However, being a practicing attorney who isn't a completely miserable scumbag puts you in a minority position as well. Let your conscience be your guide... and if you don't have a conscience, just try to stay within ABA ethics guidelines if you can.