Your shammy DPS shouldn't be low compared to other DPSers in similar gear. My shammies are usually at or near the top of my DPS when I'm running 10-mans with similarly geared mages, locks, hunters, and boomkins.

They pull more than 3K DPS without bloodlust, though that is with a few 10-man buffs, though I'm having to put in more +hit than you should running heroics since I have to hit the magic 288 +hit to cap it (with a boomkin fairie fire +3% to hit buff). My teams are fairly well geared. About 2 months ago I made the shift from /castsequence to click DPS macros on all of my toons. Took forever to set up, but DPS went up across the board. However, shammy DPS saw the smallest jump, so a good /castsequence for your shammies is probably reasonable to stay with for a while if you don't want to rewrite macros right now.

Information about the /click type DPS macros are also in Fur's thread.

My shammy's names are Stonecow, Blazecow, Windcow, Pantero, and Windcow on the Magtheridon US server if you want to look them up for any reason.