1. teleportation cost is not updated after learning teleportation II - the cost remained the same as it was before the skill was learnt. Reloading the game fixed that. Same thing after you level up - teleportation cost still reflects the old total energy level (the actual cost when teleporting is correct, though).
2. I started a multi-player quest, and a dialog popped up in the bottom right saying "waiting for other players". I didn't press "ok", a player accepted the challenge and we played the quest. after coming back (not winning), the dialog at the bottom right said "not enough players accepted the challenge" or something similar. this happened twice. when I won the quest it did not happen.