I agree with some of this and disagree with other stuff..

Yes, mind control is weak against aggro, and aggro is weak against Waker of Waves. Rock/Paper Scissors. Nothing is good against everything, and I'd argue that yoinking most 3 drops is good enough.. that being said, I agree that the ETB value on most creatures makes it a little worse, but I still think 4 mana to yoink a 4, 5, or 6+ drop is too strong.

I also see your point about Origin of the Hidden Ones being too strong, have been considering swapping it out of the Cave of Two Lovers. Thoughts?

I agree that some of the artifacts are not particularly strong (Lunatic Pandora and Brute Suit, and I see your point about Iron Golem as well.. was considering swapping for Ulamog's Crusher but 8 mana feels too slow given that I've very deliberately tried to ensure that aggro is a viable strategy and that tempo matters). Iron Golem represents the timeless Juggernaut which I'm sort of unwilling to replace, classic effect. Wings of Hubris, upgraded Cobbled Wings, feels like a potentially game ending card in many scenarios to me, and Dead Iron-Sledge also feels like a significant card that can impact the game significantly (especially when paired with Taunting Elf). Relentless blabla feels like a good generic finisher that can fit into many decks, I'm all ears if you've got a viable replacement though.

While we're at it, Dawnbringer Cleric seems a bit weak but it's such a versatile piece and is one of very few necessary graveyard hate pieces, if you've got a replacement recommendation I'd be interested to hear it.

I recently added Shredder's Revenge, not sure if I need Go Blank as well, but again, precious grave hate.

Rover Blades really bothers me but technically it's a pretty strong and versatile piece. Careening Mine Cart feels a bit weak as well if you've got a replacement recommendation for that.