I'm making a survival build for guardian druid for dungeons, lfr and a bit of battleground. I have Soul of the Archdruid and Dual Determination. Now I got Cinidaria, the Symbiote. Should I choose it over my existing two?

hello, so i am following this deck - https://www.icy-veins.com/hearthstone/elemental-mage-deck and i was wondering which card i should buy next and i dont have much dust left. I need the following cards
Primordial Glyph x2
Pyros x1
Arcane Keysmith x2
Blazecaller x2
Frost Lich Jaina x1
 
I have 1945 dust left with the option to disenchant "Archmage Arugal" with a total of 2345, because i dont use it, nor do i know if its any good?
 
 
I can either go with x2 Primordial as the guide says this is needed for the deck + x2 Blazecaller for late and x1 Arcane Keysmith? but then  i wont have the pyros for early or Jaina for late.
 
Or i can go balls out buying x1 Frost lich jaina and x1 primordial glyph ? / Or just Pyros and x1 Primordial. I dont know.
 
My last scenario is buying Frost lich jaina and x1 primordial by selling some rare cards, then use "Archmage Arugal" instead of Pyros for the time being and combo it up with AI for 2 extra cards, and hope its something good.
 
 
 
any help is grately appreciated.

As a retribution Pally should I equip the Insignia of the Grand Army instead of either Soul of the Highlord or Chain of Thrayn.  Could not find in the icy-veins guide about this ring.
Thanks
 

I have enough dust to finally craft a legendary card but no idea  which card to craft. My deck has dk anduin in it. It isn't a top tier deck. This is my deck list> ### 
# Class: Priest
# Format: Standard
# Year of the Mammoth
#
# 2x (1) Holy Smite
# 2x (1) Inner Fire
# 2x (1) Northshire Cleric
# 2x (1) Power Word: Shield
# 2x (2) Divine Spirit
# 2x (2) Mind Blast
# 2x (2) Radiant Elemental
# 1x (2) Shadow Word: Pain
# 2x (3) Kabal Talonpriest
# 2x (3) Tar Creeper
# 2x (4) Lightspawn
# 1x (4) Spellbreaker
# 2x (4) Tortollan Shellraiser
# 2x (5) Holy Nova
# 2x (8) Free From Amber
# 1x (8) Marin the Fox
# 1x (8) Shadowreaper Anduin
# 
AAECAa0GBPIF1wqQ0wKk5wINlwL4AqEE5QTJBvYG0QryDPC7AtjBAtzBAsrDApnIAgA=
# 
# To use this deck, copy it to your clipboard and create a new deck in Hearthstone

So, I'm currently maining Blood DK and that's the spec that I've gotten my 4 legends on. I do occasionally use UH and was wondering which of my legends would be most effective for it. Just a foreword, all of the gear that the legends replace is about equal; all 915-920 and don't cause any major stat changes so its not like using one legend over another causes me to use a bad piece. I have Soul of the Deathlord, which is the one I use most on UH, and I have  Shackles of Bryndaor, Archimonde's Hatred Reborn, and Prydaz, Xavaric's Magnum Opus. Does the Shackles passive work on UH, if so, could that be a better boost for Val'kyr[Dark Arbiter Talent] (b/c you can cycle more RP)? Other than that I'm just wondering which out weighs the other, STR or the secondaries?
Edit: and just in case it makes a difference, my talent build is; http://www.wowhead.com/talent-calc/death-knight/unholy/c75z