My problem with it is that you generally win after playing Dream halls regardless of your opponents' actions. Even with a naturalize, you can play 1 spell for free right after dream halls resolves, which means that something like conflux would literally generate so much card advantage, you might as well give up. :-/
I think I'm just adding cards to this list though, since it's just a note for people anyways (and yes, it MAY end up having cards banned).
Next up on the chopping block:
Mind's desire
6 mana sorcery that lets you shuffle your library, and then exile the top card (to which you can play for free). It has storm, which lets you copy this once for each spell that was cast before it.
Again, it's another card that can go infinite, wins games anyways without going infinite, and is generally unfun. The difference here is that this guy is...well not counterable except with something like mindbreak trap. This guy might warrant investigations. :3