Alchemist - The Ganker

It would be best if you have some early game armor, your item build opts for less beef and even for a Ganking Alchemist, having HP problems and very low armor early on just makes you prone to being kited down or worst, counter-ganked by any Ganker with Medallion of Courage.
The skill build looks more of a Farming Alchemist rather than a Ganking one Actually, if you wanna play gank, it'd best if you max Concoction first as to increase the duration and damage dealt.

Tempted to downrate as no Armlet, but will leave it for now under the assumption you are planning to add more to the guide as it's currently lacking the guide part.