You're going to want to keep a pad of paper by your keyboard, because taking notes is the only way to keep track of all these quests and mini-quests. The game's clunky interface makes it a real chore to do so otherwise. Each character's quests are listed separately. In other words, you'll be jumping between a whole mess of screens just to figure out what you have to do next. A group journal listing all of your quests would have been a much easier and more logical way to handle all this.
Inventory management can also be a patience tester.
Quests, especially the major ones, involve lots of crystals, amulets, and oddly named keys. Throw in the few minor quests you're on, and pretty soon you've got a decent collection of arcane junk. Here, again, note taking is important, because at times, you're going to be carrying around more keys than a night manager at Burger King. Character advancement, especially among the spell casters, is never completely explained. Neither is the training system that one enters when joining a guild.