I have a couple of caster suggestions.
Please, please, please, please, look at Channeling! Max channeling and if a NPC hits you for 1 damage it interrupts 75% of the time. Levitation floating downwards also affects channeling even though you remain stationary.
Also -
A necro suggestion/request - Please put Torment of Shadows (Necro epic clicky) on a -50 MR check, like the rest of our movement snare spells. Currently it is on a 0 MR check making it very difficult to use.