tbh knowing Shiro she's more likely to reach the top of the mountain and become a god or something equal before choosing to be someone else's champion.
yeah there is but I remember one of the spirits saying that the spirit capital moved around as they couldn't stay in the same place for long. I can't remember which chapter it was in though.
For some reason now that Shiro has named the mountains I can just imagine that that's where the spirit capital will end up as there's such a large amount of mana there.