First, Court of Stars and The Arcway will now unlock account-wide once each individual dungeon is completed once on an account.
Second, World Quests will no longer have the "friendly" reputation unlock requirement for secondary/alt characters. Once you hit 110 on an alt, you will immediately receive a quest to speak with Khadgar to receive your Flight Master's Whistle and unlock World Quests, as long as you've already unlocked World Quests on your main.
Hope this answers your concerns! :)