As a developer - I think it's a very good idea.... except the annual fee. I think the 30% should be enough. Why? Because as a developer who runs his own company, I don't know when I'm going to have time to write anything and when I'm not. I'm not going to put $40 down just in case I manage to get something releaseworthy. We're in such a small market, I'm not sure about subscription model at all. Percentage of profits is fine, though.
I think maybe a subscription fee may be more worthwhile when/if this takes off, but not until.
Incidentally, I'm still not sure what Project Metropolis is. If it's a website, then that's no good- there's plenty of portals already. It needs to be an app like Jack - but doesn't Jack already do that anyway...?