You are WAY over hit cap. Change hit gems for strength gems. I don't know what trinket to put in instead of the Mark of Supremacy, but someone will. You don't need the hit. I promise. You don't have a belt buckle on your belt. There aren't any enchants on anything except bracers and gloves.
Your legs are PvP w/ sub par gems. Your gloves aren't gemmed. You have no tier gear, so no set bonus. Ret doesn't really have a set rotation. I personally: Judge, CS, DS, Consecrate, Exorcism when Art of War is up, and I'm sure I've forgotten SOMETHING.
Seal: Many Mobs = SoComm, Single target = SoCorruption
I'm don't play ret very often, but I still contribute acceptable dps, in the 5 - 6k range, given my ret gear (which blows). You need to get some set pieces, and there are others here that can tell you which ones would help you the most..