It depends! Generally, reviving after dying of unnatural causes will preserve the rank (and size), but a natural death will reset both on revival. There's a bit more to it I'm keeping to myself for now, but that's the gist of it ^^
No, it's accurate! ^^
It's just that every other witch you fight (in this demo at least) is in fact rank 1. I do actually have a lore explanation for that too, especially for the more powerful ones, but the main reason I wanted it to be that way is that I prefer to have the player discovering the higher ranks through their efforts of amplifying the characters after they join your party