I haven't personally tried to create a tanky shaman, but from my experience I'd say you're gonna have some trouble.
All your gearsets are light armor, so physical mitigation is always low. In my heal gearset, I use mostly armor talismans and a few wounds talismans. That still only comes out at 2600ish armor with an armor pot. I do have nearly 10k hp with a lini which gives me a nice buffer, as well as 900ish willpower for some OK healing output.
I also don't think any of our armor comes with much avoidances. You can get high disrupt in heal spec just from having lots of willpower, combined with deft defender you can get somewhere around 45-50% disrupt. But parry and dodge? You're gonna struggle to get over 25-30%. When you take into account strikethrough, your actual avoidances will be half that.
So.....
Survivability on a shaman comes primarily through self-healing and kiting. Toughness is a viable option. Our gear doesnt come with much toughness but using all toughness talismans you could probably get to 400-500 toughness. You will notice that and it'll effective boost the value of your self-healing.
I would probably recommend going with DPS gear and the following spec:
RoR.builders - Shaman
Put remaining points wherever you like. Main points from this spec:
Wazzat Behind You - automatic detaunt. Genuinely good tactic for making you tanky, especially if you're being attacked by multiple people.
Waaagh! Frenzy - dramatically increases self-healing when in DPS spec. Your DoT, Bleed Fer Me, now has a good base heal (tho you will do less dmg) and more importantly, I'll Take That can now be cast whilst moving AND has a good base heal. When I've used this tactic, this regularly heals for 1k+.
Fury of da Green - one of your main forms of self-healing, you have to have it when DPS spec and solo. If you're blob surfing, you'll have opportunities to use it a lot, it does AoE damage and will heal those around you which will get you renown.
Sticky Feet - your main tool for helping you kite.
Now, if you run with regen gear (grimshimmer + 2x fleshrender jewels), stack toughness, kite well AND keep your self-healing going, you're gonna be pretty damn hard to kill. Will you be able to kill other people? Sure. You'll still be DoTing them up and slowly burning them down as you kite. I'll take that can still do decent damage on the move too whilst healing you up. If you get some distance between you and them, you can use you're bigger hitting skills.
But, dont kid yourself - you're still a light armoured healer. You're still gonna get targeted a lot and killed a lot.