Adaptive Automaton is a really good idea.  I thought about mana duplicators like guantlet of power, mana flare,     guantlet of might.  I was worried they'd also boost mana for opponents playing red and they'd be able to pay more of the mana cost for Kazuul.

You're right that Mindsparker doens't really fit.  I was thinking of him as a decent blocker because of his first strike, but I think you're right and he should go.  Geargrabber & Rustmouth are good ideas - kind of hate against artifacts/equipment, and if I can make opponent's creatures attack I should have no problem connecting.

I think your right that control is going to be a problem.  I don't see any way to recover from sweepers or deal with really problematic creatures - say something unblockable or even a lot of flying.  I think green has some tools to deal with either, but that'd be a different general and deck - Ruric Thar or maybe Stonebrow or Xenagos.

Incidentally, I played against a Rosheen Meanderer deck that was heavy on hydras with X casting cost - it was neat, I was genuinely impressed.