Hey
This would be my pve spec
http://goo.gl/y9POc1
One arguable feat is probably "Faithful in Set" but i like as it will improve your blue heals by 10% without having to do much.
About rotation : Well i dont have a very strict rotation but there are a few things to watch.
Usually i start a fight like this : Storm Crown , Blue heal , Idol of set , Thunderhead , Storm field , green heal
After this use Charged blast , lightning sparks , vital shock ...
Keep always on cooldown : Storm field , thunderhead , idol of set storm crown and the green heal
Give the tank some time to build aggro before casting Aura of Nebthu together with Storm field to further increase your dps (maybe at second usage of Storm field but depends on the tank ofc)
Vital shock is very nice as its hits will return HP , Mana + stamina to every friendly player around the target.
Your blue heals are a good source of dps as well and unlike PoMs you wont get into big mana troubles when you use them every few seconds
If you find yourself ever out of mana just use "Blood Mana" preferrably together with Storm field and Aura of nebthu and your mana pool will be full again in no time .
And dont ever use lighting strike , except you cant reach the target like in entity , but iirc correctly there is not a single HM encounter where you wont reach the boss so dont even take it on your hotkey-bar
About AAs : Decisive + pressing strikes as usual
Steadfast Faith will be needed for some encounters so get it fast
Enchanter
About the gold perk it is up to you what you will go for first:
The Idol is an additional big heal (even decent without much heal rating) , but does very little dps and should get to the 4th stack before being used (stays up for 1 minute)
Coils of the Serpent is the second one I would recommend it will give you more than decent extra burst and will most likely get you aggro in no time if used together with Storm Field and Nebthu
hope that could help you a bit ^^