Yeah, there's so many faction vendors around the place, it's very likely that some spells/songs are going to be gained from at least a couple.
Got to say though, these factions must really be set up for a year long expansion as I'm farming a few places for missions and not seeing a trickle of faction chance on them.
Probably why we've not got definative info on this stuff yet, people have been grinding to 80, now they're doing the quests. Won't take long I'm sure till we know the mechanics exactly.
But SteamFactory for our aura? Ouch, that place is rough.