Add PvE spells you've stolen. It's pretty easy to figure out what can and can't be stolen in PvP, and it would also make a HUGE list. Keep in mind that not all pve mobs have mana pools, but they have abilities you can steal.
H Deadmines: Holy Fire, Seaswell
H Shadowfang Keep: Forsaken Ability (off Tormented Officers)
Halls of Origination: Shadow Bolt, Fireball.
Throne of the Tides: Chain Lightning, Lava Bolt (Shaman boss)
Vortex Pinnacle: Lightning Bolt