I like the idea of bringing Energy into Modern, as having Ugin as a payoff for
Aetherworks Marvel seems pretty "auto-win". I tend to agree with you about Machinations and
Live Fast. They're just okay, and you can probably do better. Maybe moving up to 4 copies of
Glint-Sleeve Siphoner, and
Longtusk Cub would be a good replacement for the 4
Live Fast. Then you still have extra card draw from the Siphoner's and you have an aggressive energy producing body to boot.
It might be a bit hard to cast, but
Demon of Dark Schemes seems like a great payoff card here with all the energy production.
Aether Hub also seems like a perfect cards, since it helps with the mana base, and you should always have enough energy for it.