To set up spell lists, just right-click on the little (red?) square directly below the spell gems (the Spellbook icon). This will give Load, Delete and Save options. Just memorize the spells you want in a certain setup, and save it. You can save only certain spell slots and leave the rest blank. Meaning, I have a saved set for my 'permanent' spells (FD, lich and pet haste). The other five slots are left blank. Then I have certain spell sets for the remaining slots, ie all my undead spells, or my 'travel' spells. That way you can load up certain spell sets without spending the time to re-memorize all the spells.
I never went to the Library in Kaesora (on purpose), I spent all my time in the Church/Five Towers area. That area is almost entirely undead, though sometimes a spider or a spermie will wander down to the top area. I undead pacify all mobs in the immediate area, pull with undead slow, hit it with the long undead dot, then whatever else is necessary (darkness, another dot, lifedrain or undead nukes, etc) and can pet heal when necessary. This applies to other undead areas, like Lower Guk.
As for focus items, one of the best things to get is Burning Affliction, since we're so dependent on our DoTs. Kobold-hide Boots are great for this, with BA2. Mana preservation and spell/affliction haste are also good foci for us to have.