Yes, we also manipulate ambient energy. The question is what is the source of said energy? Some say it comes from the Goddess, but I do not think that is true. I believe it is intrinsic to the world. That other worlds function similarly without Sothis would seem to lend credence to the idea of the 'aether' being separate from any particular divine being.

No. Is that normal? Sothis is the Goddess - she is responsible for everything. Her children are more like what you describe having different activities, personalities, or qualities that they favored.

My classmates are from versions of our world that differ from mine. I am dead in Claude's Fodlan. So the version of me that they know is not this version of me, and vice versa. The timelines seem to match until we went to the academy, however, so most of our personalities and preferences are the same.