Don't do this with quests.
Mind you, one quest would work, and would have all the advantages of a quest in your high fantasy world, as an iron-clad and all purpose excuse to move your characters around so that they keep encountering new things.
It's the art of getting your two or three characters on quests to bang into each other or hear about each other at interesting times to move the plot forward.
Too late for me now. I could jettison this and write another story entirely, but I can't rewrite this one to have at most one quest.