No, it can not be tweaked. Un - upped decks cannot beat most FG's with a GOOD winning percentage. And even if you upped all of this deck, it would not work. You have no way to heal yourself, no way to sustain all the attack and the Critter control, and no way to rush their 200 HP out of them.
Also, you mentioned you was fighting decay? oO
It's kind of impossible to beat decay with that deck because of this sole reason --
You need to GROW your lava golems, to grow you need QUANTUM, and decay > quantum. So either you had really really incredible luck, you h4xxed it(
) or you thought it was decay but it wasn't. But no, there is no way to tweak this into a FG farmer.
Sorry.
Edit : UNLESS you do some major changes. But then it wouldn't be tweaking, it'd be more like.. reforming.