Wow, I was just thinking about making a game like this. I love the Starcraft 'Verse, and I've got a couple of ideas already.... I could be the "seasoned" GM if you want. I've run a couple of games on E and other places. (My most recent, Peace Summit, you can find in my posts, if you want to check my credentials). They were all free form, although I wouldn't be against using a simple system to help smooth out combat.
I want to make sure about something though: I focus more on story than sex in my games. That's not to say there isn't any smut, but I'm a fan of "Let plot dictate sex, not sex dictate plot." If you're okay with this, I can whip up a few ideas and a character sheet in a new thread tomorrow night (ugh, class all day tomorrow). If not, I'll make it anyway, and you can ignore it if you want