Getting the stark first may also not be such a good idea. You have no damage. I think the greaves and your passive should be enough AS for the very early game, and you should go Triforce first (some life/mana, some AS, some damage, etc).

Something like Emblem -> Greaves -> Phage -> Brilliance -> Zeal -> Triforce -> Stark may give you a better early game.

As you are AS based, i think a Madred could make his place somewhere (i would not get Infinity Edge considering you don't have many crit chance). Considering this, i'd remove the 3 mastery points in Lethality and one in offensive mastery, and get 4/4 Sorcery and +15% MP (you still have low CD spells, use them :)).

Also, why don't you get a level in Null sphere at the begining (lvl 1, instead of Pulse) ? The silence effect could save you many times, grant you a kill (no heals, no summoner spells like flash, etc), or be used as a disabled on some casting spells (Nunu, Fiddle, Katarina ...).

I saw you talking about this on the forums earlier; after trying this out i'm kinda surprised i was keeping my head above water. Flash and exhaust were great for this build, but the build in general is waaaaaaaay too slow. You lose so much potential and utility from the skilling order, but getting that extra armor pen from W DOES help win laning fights. I can see how you can have SOME success with this build, but it's too slow to be effective in controlling a game.