This post is more aimed for the moderators I guess. I don't know if it's already been brought up but here I go:
1) Rescue Operation (part of the Clash Chain quests)
-> the guy does not move after you click the "Let's go" option. It say target is busy.
2) Angry Fire Elemental quest
-> Angry fire elementals do not spawn after killing many of the fire hybrid mobs near the plant
3) Sleeping Insomnia quest (Syrbal pass - lyndon camp)
-> After clicking on the skeleton remains, the quest does not complete. Also, the ghost girl disappears after completing the fog quest so cannot complete that quest either.