Well, the way Mana shield works is like this:
You lose two points of mana for every % of damage indicated by the skill level of your mana shield. (until your mana is gone). Adding to telekinesis helps with this.

You can figure the medium with what you prefer. On my blizz sorc i had 1300 mana and 2.3k hp with max telekinesis.

p.s: SOVEREIGN SUCKS AND IS EZPK...noob