Nice Mod!
I was extremely disappointed that a colonial nation as big and powerful as Portugal did not appear in the game. (I'm even pleased with Purple). With this mod, I can finally play as them.
Now, as with every minor power mentioned, I have 2 ones I like to suggest.
The first one is New Prussia.
Here is a Mod that includes it. Now. I think being able to play as Germany would kick butt in my opinion, but they would obviously be minor.
The other would be (and have no mod to show you, sorry), would be New Ottoman (Maybe New Turkey instead? It sounds better). Age of Empires 3 proves that they indeed have colonies in the New world, and the religious differences would be fun. They could have an X amount of negative relationship to all European empires (You have followed the sway of a heathen religion, anyone?). Also, heavily converted Native nations would also have a negative bonus. However, they could have a chance to spread Islam to the New World. Heavily missioned states by the Turks will cause that tribe to have the same negative bonus. Finally, some aesthetic changes would be in order. Instead of crosses, they could generate crescents (If anyone has a better idea, do share)? Also, Churches and Cathedral would be changed to "Small Mosques" and "Large Mosques", respectively. Even with all of this work, they would probably be minor. If needed, I can help with New Turkey idea-wise.
Anyways, I have an Idea. The Big 5, England, France, Spain, Holland, and Portugal will always be major. However, there could be an option for all the minor colonies (New Sweden, New Prussia, etc). The first one will use the current idea, that the Minors aren't playable and come around 100 years later then everyone. The second will have them playable and arrive with the Big 5 and have a change to be big powers. You may or May not add some bonuses to the Big 5 so that they would have an edge, but for the most part, it's anyone's game. That would open up some interesting possibilities.