Well, bless your heart, Dad! You can come help my troop anytime.... however, here's what I have heard from my moms about Dad's participating:
About the former (male) troop leader - "Oh, he was just great, the way he worked with the girls and they all just loved him. But you know, he was always SO CAREFUL not to be alone with the girls and that made me so much more comfortable with him...I wondered about him at first, you know, but he definitely was a great leader."
About another dad who briefly had his daughters in our troop, but there was a custody issue and they went back to mom pretty quickly "Boy, he really makes me nervous, kinda creepy the way he talks to the girls." This guy bought a sash for a girl not his own daughter because she didn't have one and the girls' mother went ballistic. As far as I know there was never an actual problem but this poor fellow was trying "too" hard. The problem solved itself because of the custody thing anyway but I was a little nervous
So, I know you understand how nervous parents are about their precious baby girls, and if you address that with great tact and delicacy I'm betting your troop will end up absolutely loving you. Leader of the year in our service unit last year was a dad, and he's an absolutely GREAT GIRL SCOUT!