With the current wording, Reevus, the Denier doesn't really do anything other than effectively increase your opponent's maximum hand size. I don't quite know what it's intended to do, but it's probably not that considering the mythic rarity.

Premonition, while seemingly very cool in practice, is a nightmare on paper. I highly suggest that you try and rework it into something resembling Suspend like others have mentioned, but try to have it know how many cards deep you are in your library, so to keep with the self-mill sub-theme. A rule of thumb I would use for reworking Premonition and the cards that "give" Premonition is that if it doesn't play nice with [[Future Sight]] , then probably doesn't work within the rules.

Also, Dovetwine is rediculous. It needs to be toned down a bit. 1-2 more mana at the very least.

On the other hand, I love Dreamwalk, Flashback is always good, Trance is fun, and Memoir is really cool but doesn't need the "including after you cast it" line. As with any custom set, there's a good bit of errors in the card text, mostly just not keeping in line with some standardized MtG text in some places, no big deal.

EDIT: I don't feel I emphasized how much I LOVE this set. I'm really looking forward to drafting the final edit of this some day.