Machima Megaform is a horrible card,but really why would anyone sane run it?It's an useless waste of space + it kills your Gearframe,kick that shit out!
Kabuto is just terrible,his + really is not something you need,you should just remove it for like 3 Copies of Giant Rat (All your monsters have 1000 attack,don't they?).
Geargia searcher?That is not really needed,as you want them in the deck so you can summon them with Giant Rat,he's pretty much your best monster from the deck besides Big Beniki.That Double Attack Quick-Spell won't work as Samurai use their deffto attack and playing it because of 3-5 Machines is just a waste of card space.If you kick Megaform there is no reason for Trade-In ether,so yeah add Pot of Duality,you will be speacial summoning in your opponents turn (Rat) not in yours.And um Soul Big Bang Samurai's a nice card to go with Soul Charge I guess.
3 Upstarts with 3 PoD 2 Gear 3 Rat should speed up a deck a bit,that's all.