I'll put up my thoughts on this when I get my lunch break. They're generally positive though.
First of all I'd like to thank you for taking my characters' unique position into account when you made this. I appreciate it. If I may abridge what you're saying, the partner digimon will be getting stronger as they shift through their evolutionary forms, except mine who will be gaining power from combat experience since Champion is its natural state. With this in mind, if Rosencrantz at some point in the plot overcomes his current state and unlocks Rookie and In-Training forms, (something I was planning to do after hitting Mega the first time) would I be switching over to the Dusk/Dawn format of gaining power like everybody else?
Aside from that I don't really have any concerns, especially if we're going to be considered pretty much equal if pvp crops up. A few years ago I would have been against trying to catagorize this sort of thing in a free-form RP, but I've seen since then that sometimes you need a system to guide things along at the very least. Don't be surprised if I try to beat power with guile, though.