I've got to agree with a lot of the frustration here. I picked up CoP during the sale, to try out my first Native American game as Iroquois. It was a lot of fun for a while. I don't mind a lot of the changes in the patch. The colony growth based on tech slowed me down, but that's fine as it's kept me from blobbing too easily and slowed down the Europeans. But when I managed to reach Portugal's Arctic colonies in the early 1500s and reform government, I was dumbfounded to find I had to be 24 techs behind to Westernize, and was currently only 3 techs behind. Losing the native ideas that reduce tech costs by 100% would make it even harder to keep up. Now I'm not sure whether to spend the time trying to mod my game or just give up.
I agree with the posters who suggested a more piecemeal Westernization system would be more interesting and easier to balance. There could be individual decisions that reduced the tech penalty in specific areas, so successful non-Western countries could close the gap, and determined players could eventually reach Western levels without being gamey. I also think the new policy system could play into it - have policies like "Invite European Administrative/Diplomatic/Military Advisors" that would activate the tech-boosting decisions/events over time while having side effects like unrest, provinces converting, etc. Alternately, European nations could choose to offer advisors in exchange for transferring trade power/cash.
The current reforming government system should also probably be worked in with a system like this - it's a little silly for a native council with all tech 1's to instantly become a feudal monarchy with techs in the 7+ range. Meeting the requirements to reform could instead add a series of events/allow policies to quickly gain a few techs and choose how to shape the government - playing a nation with strong traditions of representative government like Iroquois, for instance, I wanted the choice to become a republic. Even better would be if there were advanced forms of the tribal governments, just as there are now military units for the whole range of tech. Religious changes could also be worked in, offering the choice to convert to Christian (causing instability but making diplomacy/technological exchange with Europe easier), to stick with the old ways (being the most stable choice but with the drawbacks of the old religion and less tech improvement), or reform the religion like in CK2, a middle ground that causes some instability but could get rid of some of the drawbacks of remaining pagan.