Religion will always be a big part of African lives take it or leave it, and honestly without it Nigeria would be an even bigger mess than it is right now. It has given social structure to a nation without it and has been one of the few uniting factors in a nation of over 1000 tribes.
As for your second point it would be foolish to believe that if AAs had their own nation they would act differently from what is happening in Africa, you would not even be African American you would just be African. with the same problems facing the continent from centuries of white rule and exploitation.
This belief that Christianity encourages white worship is beyond stupid, the white worship that can be seen from Africans/Asians and all other minorities comes from the History of colonialism and rule over these peoples, combined with the wealth and success of the west and Europe (Ironically derived from this same exploitation) has created a real sense that "whites are superior" In Africa and Asia. That is why in marriages white men or women are always seen as acceptable alternatives in African or Asian Families. (Altho i will admit the incorrect portrayal of Jesus as a white man was indeed another tool used by whites for a type of suppression like you said, still most Africans i know and talked to do not place this in high regards for how the feel about whites. Financial success is the biggest reason stated when i asked)
Another Factor is Pure Jealousy, Africans think AAs are stupid for wasting the opportunities given in America considering the poverty they endure in their nations, what they do not understand is AAs have been under systematic oppression along with the destruction of the family unit as well as social and economic repression that is ongoing today has created an environment in which no race would be successful. The Fact that African Americans have even made it this far is a miracle in itself..