Also, there are some other useful things to know that are just unclear and as far as I know not mentioned anywhere ingame. The two I have for my current progression point are:
* Where do I find Velvetia (and co.) to be able to ask her to grind soul gems for me? Those three vanished from Fortus after doing a Lucina warp to one of the demon general areas, and I was kind of relying on that ability because grinding got boring a while ago.
* How do I take off the black slime (forgot her name lol) clothes? This equipment is a lot less useful than any of the similar clothes and hinders soul gem grinding.
These are things that I'm pretty sure were added very recently (my main events count is at 99% and the last one is probably behind the soul shard cost to the next area that I don't want to grind, and these games tend to be made somewhat sequentially) so it makes sense that there wasn't enough feedback to know that finding this information is too unintuitive to find yet. Content later in a game is almost always less polished than earlygame content just due to less people giving feedback about it.