Ya'll need to stop comparing Mass Confusion to Seeds of Confusion. SoC is plainly too good, that should be obvious to anyone who understands the rationale behind the AoE control nerfs of yore. Specifically, it shouldn't be possible for one player using one power to permanently control a group of enemies so they can't attack, and SoC can do that with aplomb. That's not to say Mass Confusion couldn't do with a slight buff, but nothing specific to Mass Confusion, IMO. Rather, removing the acc penalty on AoE controls (Mass Confusion could instead have an acc bonus), and either a slight increase to duration or decrease of the recharge time.
Personally, I think Mind's problems are mostly on the Controller side; no pet and no AoE immobilize are not much of an issue for Dominators, but it hurts Controllers' damage output. I think the best solution to that is to make Terrorize status a valid status for Containment, and to increase the damage of Levitate, Mesmerize, and Dominate so that they do the damage of normal ranged attacks with their given recharge times. It would also be cool if using Levitate on a Telekinesis'd target made it AoE, toggling off Telekinesis in the process.
As for your other suggestions, I like making Mesmerize and Mass Hypnosis knock down enemies, so they have to stand up after the sleep breaks, though that sounds like it might be really complicated to implement. Right now knockback breaks sleep, so they might have to implement an entirely new mechanic for it, not to mention it might call for animation work. The Dizzied mechanic also sounds like it could be cool.