Seems reasonable. Cool with various incidental themes (like, uh, if you had a Thought Scour cube?) and can be combat tricked and do a late-game Goyf impersonation.
I tried to re-read the rulebook a while back and couldn't understand why it was so damn complicated. I probably never played a game correctly in my life.
I'm really okay with "splash for card selection", because those games sound really fun. Who doesn't want to get a Brainstorm / Courser / Domri deck going?
Most people already run Preordain/Ponder/Brainstorm, and all of those can be converted at no cost. I could probably run 5 and not really notice an impact. Does blue need depth to do other things if it can filter all day long?