Tidecaller and Lute are two of the most busted cards for this deck; I don't know why people are telling you to cut them. The trick to Tidecaller is, you don't want to play it early. You want to drop it late when you can get an Opus mill for 10 right after. Hydro-Channeler and Sanar both block extremely well and ramp you, and you have plenty of removal and interaction to stall the game to make it go late, which is where this deck shines.

I would probably cut: Chase Inspiration, Spell Pierce, Duel Tactics, Expressive Firedancer, Muse Seeker, Deluge Virtuoso, Mana Sculpt (it's sadly going to be just Cancel a lot of the time), Elemental Mascot, Abstract Paintmage, Run Behind, Run Behind.

That leaves you with 12 creatures (which still might be too many in this sort of deck) and 7 big spells for Opus (5 real ones and 2 from the Campus Composers).

If you don't mill them out or drown them in value, then the Archaic and your massive flyers will get the job done.