All in all, I came away from this deck feeling like The Aetherspark is actually a good card, perhaps even a great card
I prefer Cabal Initiate a lot, especially because Viashino Lashclaw become a Grizzly Bears in the late game
While the Turtles flavor of the card has mostly kept the enchantment in Ninja Turtles-themed Commander decks so far, I think Endless Foot Assault is actually better than that and worth considering in Aristocrats-style decks thanks to the number of bodies it can make for free each turn, and also in some aggro decks, especially those built around attack triggers like Isshin, Two Heavens as One
However, for the other reasons you stated, it still may not be necessary
Speaking of Explosive Vegetation, Advocate interacts pretty favorably with that card as well, jumping you from four to six mana on turn 4 to upgrade it into mid-game form