Wow it's really fun to see this much interest, after the first day I started to think this was doomed. 
Expanding the group is a possibility, at least as far as adding a jounin commander to the team. since we will follow the main story as closely as we can manage I think adding more genin would be a problem. Of course, I'm open to all possibilities, so if you think there is a way around it I'd like to hear what you have to say. 

Dylan:
I might disappoint you now, but the system I have in mind deals with powerplay and meta gaming in a totally different way, by embracing it. 
To start off we'll try to stick to the main story, which means that everyone will know what the next step is at all times. We know the strengths and weaknesses of our opponents from the start as well as their techniques and special traits. Powerplay will be set to "open", which basically means that you're free to include the other players characters in your post because they'll act in a way we already know. Example: First fight against Zabuza - everyone will get their ass kicked. Chuunin exam written text - everyone will struggle with the text and unless otherwise specified, will try to cheat. 

The challenge in this game will be to portrait your own character, the other PCs and the NPCs as well as you can. I demand a more mature style of writing that isn't centered around the concept of playing your character, but to make the story as good as you can.