Legend of Zelda: Skyward Sword [SPOILERS]

I have a questions for those who are near the end of the game or done with it.

 Spoiler

So when looking for the party thingy for fun fun island, I accidentally accepted the thunder dragon quest. Does that mean I have to do it before doing the other 2? I just looked around in eldin volcano for 2 hours and the entrance to faron woods is blocked. I fear to do the thunder quest first because I heard it sometimes give a gamebreaking glitch.