Coiling Oracle in addition to the Elvish Visionary, Elvish Promenade I find is really good, Craterhoof Behemoth is probably better than the eldrazi and Regal Force
I use a build pretty similar to yours.
Try 2x Staff of Domination if you don't like the Curio. You need another way to combo/win.
Craterhoof it's better than Emrakul, it's tutorable and 8 mana it's more viable to acquire than 15. 2x Regal Force it's enough.
I don't like the Imperious Perfect . I would prefer +2x Scrybs instead.
What about Chord of Calling in addition to Summoner's Pact?
And Elvish Promenade is insane once Beck is cast, draw X cards and put X elf tokens in play where X is equal to elves in play, then tapping the tokens to Heritage Druid. If Beck resolves its way stronger than Regal Force for almost half the mana cost.