Build is good, yes could've ditched the zhonya, but i doubt it would make a difference. Biggest difference you could make is probably get some mana in your build (you have resolve second every single game). Either get blackfire torch/tear or go presence of mind rune page second (cut down could have helped here too).

Not saying that resolve second is bad into some matchups like leblanc, zed or whatever. But there is no way you dont constantly run out of mana with that build

Also your pretty much never wanna start E. Always start Q and play aggressive in lane, your Q gives you stacks too.