» Question » Can other people help out with class quests?

You can group up, but they're not shareable. Still, if you're stuck you can have a friend help you.

If your friend is the same class as you make sure you have the preferences option let others of the same class into your class story instance (approx wording) checked. Otherwise they won't be able to enter the instance. If they are on the same stage, you both have to do the same quest twice for you both to get credit.

the answer is yes.

but if you think you will have a higher level friend help you, you are wrong to think that

higher level players will get More exp then you the higer they are from you, the more exp points they will get, and the less you will so its highly NOT recommended by me yes you will complete the story line but you wont level up properly which will make it harder or even impossible to finish/move ahead with your story due to dependence on a higher level friend.