Wow, I just wanted to say I am absolutely blown away by these civs. I played a cultural Tibet game the other day, and it was one of the most unique and interesting experiences I've ever had playing Civ. Going to try out the Nazca today, I think.
I just had a couple bits of feedback I wanted to share.
1. With the Tibet civ, it was very difficult sometimes to keep track of what units were giving me what culture, exactly. I'm guessing adding the correct information to their unit text would be difficult? It would make them much more fun to play and plan with.
2. Is the horseman replacement supposed to be spammable? It doesn't require horses right now, so you can just crank them out and gain oodles of culture and a comparably stronger military than pretty much anyone else in the classical era, if you've got hills.
3. On the Polynesians - and specifically the Maori. I read somewhere that you were going to split up the Polynesians, which I wholeheartedly approve of. I did want to make a couple points regarding the Maori, though. Firstly, that I and many others, I think, would argue the most incredibly ability of that civilization was its adaptability. The Maori had an incredible ability to adapt - they had to, because food was scarce on New Zealand after the first couple hundred years. The terrain and climate did not work for their traditional Polynesian crops, and so they had to rely on the native moa bird - which became extinct rather quickly. They became a society that was adept at taking any advantage it could get over its adversaries, and not blinking an eye at innovation. This aided them when European conquest came - they adopted guns nearly as soon as they were exposed to them, and by 1820 (roughly twenty years after major and prolonged contact) had developed forts and defenses against cannons. They were one of the few societies that came into contact with Europeans and achieved a roughly equal treaty with them after a protracted and fairly even war. There were other factors of course - the distance to Europe weighing heavily among them, but the Maori's capacity for innovation must be counted paramount among their virtues.
That's what I wanted to say. I hope that in designing them, you take this into mind - rather than focusing purely on their reputation as war-like peoples. They were, because they had to be - as I said, resources were scarce. But that war-like nature also folded into a technological and social adaptability. So maybe a war-and-tech-bent civ? That would be best for them, I think.
Anyway, don't mean to tell you how to build your civs... I just see a lot of misunderstanding of that particular society a lot, and I wanted to throw that out there. Thanks for your time.