Once China takes over as the Superpower, what differences will we notice?

I don’t think China would really care that much about other nations’ internal politics, and importance of religion, etc. Doubt you’d see much change there.

At the international level, relations are already very pragmatic, and religion is generally a pretense at most.

I think that things would look largely the same day to day, but our economy would degrade severely. We extract untold benefits from our status, having the world’s reserve currency, etc.