I don't think that is best solution... side quests are the story of the world around you and if you "reset" them, you are breaking that...

Guildleves, Guildhests, Fates, Dungeons, (am I missing something else?)... these should be enough, and if they are not, that is what needs to be adjusted accordingly. Keep in mind you get XP boost for classes below your highest level class.

Edit: More class-specific side quests would go a long way though. But keep them centralized to single NPC in each camp perhaps... so that there isn't a flood of Red quest icons everywhere.