Yep you need to be on level 100 now. I'm on level 100 now and the quest activated when I spoke to Faralda. The first clue was totally insane, though. Probably written by Sheogorath or something :D I wasn't able to figure it out by myself since it made no sense at all. All the other clues I had no problems with.
I was pretty disappointed when Shalidor's ghost didn't attack me or at least appear when I finished the book, "Now die, and curse my name!"
I received this quest yesterday with a 92 Destruction, although I do have the Unofficial Patch.
I'm a master Conjurer, Alterer, and Illusionist, all gave me the quest at level 90, but Destruction and Restoration can't be started at level 90 for me. Also, Restoration takes way too long to get
You don't have to be 100 on Restoration, you just have to be 90 and have completed Good Intentions.
Faralda is needed to start the quest, if you already got the Power of the Elements book from her you might be able to finish it as technically her involvement in the quest is over (but don't know for certain).
If your on a PC you can try and get her back with the commands -
prid 0001C1A5
moveto player
recycleactor
You can also try to use the resurrect console command, assuming you're on a PC http://elderscrolls.wikia.com/wiki/Console_Commands_%28Skyrim%29