My lady told me everything she knew, and everything else that she's discovered since she's been here. But you've outlined the second part of the problem as well.

I've been told that new gods receive a briefing from Amaterasu's shinki when they arrive but I'm inclined to think those shinki don't cover everything, or it doesn't occur to them to offer more information than the bare bones.

As an example, a shinki has borderlines and spells to protect themselves in the absence of their gods. My lady was told of them, but on the matter of learning to cast them or who I could turn to for guidance, I had to look through the older entries on the Bulletin Board System for further information.