That's a good build and I used it for a long time. But IMO you should try one other thing. A lot of people laugh but since I got the legendary skin I seem to always get focused on for some weird reason. Teeemo is standing right next to me people! So I made a small change, it might work for you.
Anyways, get a regen crystal first and build it into a philosopher stone ASAP. The regen makes a big difference and lets you stay in lane always and not have to run back to town. the mana and extra gold are awesome, especially if you take the Clarity skill, you never run out of mana. You will be 1-2 levels ahead of your competition at very minumun. Even if you're almost dead, stay in lane. With your boost you can always get away if you're cautious. Be very aggressive, stand between minion waves and block the enemy expos. If they get close you grab them. Some exceptions of course, but try a game with it. I once kept a guy at lvl 1 until 5 mins in the game. They had a jungler, he was solo and every time he got close he got grabbed.
Keep the philospher stone as long as you can to max the gold output and build it into the reverie at about 25 to 28 mins in. That will give you another boost that stacks with your turbo. Nothing can touch you. Then instead of sunfire I get the frozen heart. With just those two CDR reductions your ult has a 15-18 sec refresh and you can spam it every minion wave and every battle. Your power fist has a 3 sec refresh and your turbo boost is always on. Only a half second delay.
Edit: oh yeah max W first. With the philos stone you can spam it.