I'd run Top before Brainstorm in a mono blue list without fetchlands. I'd run Impulse before Top. So instead of Brainstorm, I'd say play Impulse. You aren't ever going to get late-game value out of it without fetches. Impulse late-game is still solid because it digs so deep. That's why I don't like Ponder and Preordain in this deck.. they don't dig as deep as Impulse.
I am still sold that
Think Twice is better than Accumulated Knowledge.
AK #1 draws 1 card.
AK #2 draws 2 cards (3 cards total).
AK #3 draws 3 cards (6 cards total).
AK #4 draws 4 cards (10 cards total).
TT #1 draws 2 cards.
TT #2 draws 2 cards (4 cards total).
TT #3 draws 2 cards (6 cards total).
TT #4 draws 2 cards (8 cards total).
So Think Twice draws more total cards than Accumulated Knowledge until the third one cast.. and even then, they are tied. It's not until you cast the fourth one where AK becomes better. How often do you honestly cast all four AK? Yes, Fact or Fictioning away AK is probably better than FoFing away TT but you still gain value off the card so it's not a completely lost scenario. Plus, it is always awkward when you come to someone still trying to play Intuition into AK. The AK/AK mirror match is almost as annoying as the Cloudpost/Cloudpost mirror match.
I think you
need to be running Shackles; it is a pivotal card in the deck. Maybe shave 1/1/1 on your draws/filtering? So:
-1 Brainstorm (Impulse if you take my suggestion)
-1 Accumulated Knowledge (Think Twice would be almost necessary if you are cutting an AK)
-1 Fact or Fiction
+3 Vedalken Shackles
How has Propaganda in the main deck been? I was never a fan of it, but I was always trying to fit some number in, especially when I was running Mana Leak. Speaking of which, I like it moreso than Force Spike. After turn 3, Force Spike was always dead in my hand. Mana Leak almost never was.