1. Why is the Babylonian Empire named Amuru?
The Amorites were just the founders of the empire, and the amorite rule lasted only until the kassite occupation. (Nebuchadnezzar wasn't even an amorite - he was chaldean).
I've expanded the Babylonian Empire to include it's cultural and political precursors as well. The citylist for Amurru starts with Ebla, Halab (Yamkhad/Aleppo) and other important earlier cities. Babylon is seventh on the list. The empire became known as Babylonian after the rise of that city but the people were primarily still Amorites (the rural Amorites kept that name for longer but eventually seem to have become or been absorbed by the Aramaeans). I made this change because I wanted those historically significant Syrian city states to be included and to provide much better distinction from Sumer/Akkad.
As for Nebuchadnezzar, he was Chaldean (who, ethnically and linguistically, were very closely related to the Amorites anyway), but his subjects weren't. History is full of famous leaders and dynasties whose lineage is from outside the land they ruled. If there's still space I'd like to eventually add a third leader to the civilization who isn't from Babylon. Perhaps Ebrium of Ebla.
2. Why is Sargon a Sumerian leader? He was akkadian..
Sumer and Akkad are an interesting case. There are indeed two different ethnic groups and two different languages but politically and culturally the two peoples - at least by the dawn of history - had become very entwined. There were very few specifically Sumerian or specifically Akkadian cities, though the ruling dynasty of each could be one or the other. It would certainly be disingenuous to separate them into different civilizations.
Technically the civilization could be called 'Sumer and Akkad', but that's messy in civ terms. I chose to call the civilization Sumer as it's the older name and not named after a specific city or hegemonic dynasty (other than those from the city itself, Akkadians as a people were only really called that after the rise of Sargon). There's no other term I could find that wouldn't also include the Amorites, Babylon, Assyria, etc.
3. Why are the ottomans called turks? ''Turks'' is an ethnic term. The empire we all talk about was the Ottoman Empire, not the Turkic Empire.
I understand that you want the cultural term, and not the name of the state. But their cultural definition was Ottomans. As same as the Byzantic Empire's cultural term is Byzantics and not Greeks or Balkans.
The Ottoman were a dynasty and I want the civilization to represent many of the earlier Turkic states as well. Gokturks, Seljuks, etc. I haven't remade their citylist or description to reflect this yet.
In general, I consider a civilization to primarily be a cultural entity; ethnicity, language, dynastic and political structure can of course be very significant factors but can they evolve and change over history and I don't think that a civilization necessarily ends when one or more of these disappears or is supplanted.
I don't claim to apply such a definition strictly or perfectly of course. The Egyptian civilization, for example, pretty much just represents ancient Egypt and most of its later history I'm incorporating into the Arabian civilization. Byzantium is also a noticeable exception as it could really be part of Rome (or Greece) but since it was already in BTS and there's enough historical and game content for both civilizations to stand separate (unlike Phoenicia and Carthage) I'm happy to leave it in.
And I also think that adding the Mughal Empire, the Elamite Empire, and the Frankish Empire in the next versions of the mod would be great!
The Mughals, despite their Central Asian origins, are really just a dynasty of (Northern) India. I don't think they need to be a separate civilization because, unlike the Kushan, their Central Asian history is already covered by the Persians, Mongols and/or Turks, and their Indian history is best represented as part of India in my opinion.
Elamites would be cool but they vanished pretty early in history and there's not a great deal of material available to turn them into a fully defined civilization. That part of the world is already very well represented in HR so not a high priority.
The Franks are represented by both France (Clovis) and Germany (Karolus). The German citylist has been remade to reflect this but the French one has not yet.
