Hey, congratulations! I'm still trying to get my first whitetail, period, and I can almost imagine how good it must've felt to shoot you first buck.

I think your antler restrictions are the right thing to do (and it's your own property--only you have the power to manage it according to your goals). I don't have a problem with killing any deer so long as you use/donate it, but I think there's definitely some wisdom is letting the younger ones have a chance to mature and reproduce.