Gem for intellect everywhere. Pure intellect in red, intellect/spirit in blue and intellect/mastery in yellow sockets IF the socket bonus is desireable (ie: more intellect).
Well depends on your raidsize. For 10m I'm no big fan of telluric current and i'd take 3% more critical healing chance from acuity over it (eg dropping 2/2 TC and 1/2 ancestral resolve).
Prime - if you need the mana you can think about picking up watershield instead of earth shield.
Major - Stoneclaw glyph is imho important (rather than ancestral resolve) because shaman lack other personal cooldowns, you can drop the ghost wolf glyph for it. If you don't need the resistance (eg running 25m with lots of paladins or other shaman) you can pick up hw instead of your healing stream glyph.
Aim for a haste plateau and stack mastery afterwards. Most shaman at your current gear level tend to pick 916 haste and aim for as much mastery as possible while keeping a reasonable amount of spirit (-> not running out of mana).
Regarding your hps:
Is anybody dying or are you just the lowest on the healing meter? Are the other healers complaining about carrying you? Healing meters aren't important at all, eg if it's your job to heal the tank and the raid takes all the damage & tank survives .. all is fine. And vice versa it's the same, it depends on your healing assignments and how everything 'flows'. If you're running with a disc priest or a druid keeping his hots rolling you'll have a hard time competing on hps unless you got a gimmick fight like Chimaeron.