I'm really terrible at keeping up with an RP for long periods of time, so including the setting and such, this sounds awesome! Like seriously, I squee'd internally as I was reading this premise.
One question though, how will you handle the fighting pit's combat? Just thinking that unless you're making a GM post every 'turn' it might be hard to moderate.
Did I mention how awesome this premise is? Yes? Well I'm doing it again. It's a cool idea.