The only thing I would say about growth rates is that in my experience the Americas don't stand a chance to get anywhere in terms of development as they are limited to begin with and end up with zero growth and a minus income to start. But maybe that's because it took a while for me to get there (only 60 turns left) and I never bothered with them in Vanilla so can't compare....
Fantastic mod though, really makes the game worth playing, and it feels right. Plus it is a 'proper' length now.
One of the only things I would suggest tweaking (if you have further plans) is to cut the traits building aspect quite severely. I don't think this has been altered from Vanilla and there's too much contradiction and so many traits that it's hard to work out how to nurture your generals as you want to. Specifically, in terms of economy, it would be good if you could develop 'fiscal' governors so that they could help ailing provinces etc.
Can't fault what you've done with the gameplay