for the most part:yes, though some minor exeptions exist: there are like 2 quests that are time sensitve (after accepting them) and some other minor effects: area is only available on sundays, the dates matter in the north to decide if the river is frozen.
I think a dark harp? I got it from the Redmil tower dungeon.
You need to have a valkyrie party member and equip her with the armor the NPC gives you and do some battles, the first one breaks as soon as you get hit, the second one takes a bit more hits. The third one doesn't break and your character tells you when to submit the quest. Part 2 and 3 appear a bit later after submiting the one before.
Use the search function in this thread or go to the OP and click on the link for the walkthrough/hints thread
