Aurum Vale is in the story line, so you'll have to do it. It's part of the level 50 stuff. (which I found annoying.) You don't get credit for them if you've already done them. It should probably also be noted that you'll have to do at least 2 of the guildhests at level 50 as well. The first one and there's another that's mid-ranged.

Honestly, you shouldn't ask what is part of the story line, since almost all is. You should ask what isn't. XD But those that aren't part of the story line are opened through other quests so if you don't do them then you don't have to worry about them.