[3.13]Burning things with a wall

First, how does one deals damage with FlameWall?
FlameWall deals only fire damage over time (or fire dot) which means that it scales of fire damage and fire dot multi but not added fire damage to spell like an ignite build because it doesn't hit the ennemy. This dot has two parts : a first dot that deals lower damage while the ennemy is in the wall and the second which is a debuff that last for some times after the ennemy leaves the wall and deals more damage. Just cast it on things and they should die quickly but be wary the area of effect of the spell can feel a bit weird at first.
We pick the elementalist mostly because golems are nice and the new Heart of Destruction.

main link:
Flamewall>>Burning Damage>>Elemental Focus>>Efficacy>>Controlled Destruction>>Concentrated Effect or Swift Affliction

Utility/damage:
Scorching Ray>>Burning Damage>>Elemental Focus>>Efficacy
For the fire exposure and a nice chunk of damage.

utility :
Armageddon Brand>>Combustion>> either Ice Bite>>Elemental Prolyferation or Hextouch>> flammability if you don't use a Profane Proxy

aura/curse :
if you use a Profane proxy(pay attention to put it in the left ring slot)
Skitter bots + Herald of Ash + Vitality (Recommended) + Flammability in Profane Proxy

if not : Malevolence + Herald of ash

Golem :
We have a total of 4 golems with this build, I went for a more defensive choice with Stone golem x2, Chaos golem x1 and Flame golem x1 as no other golem could fit or be useful.

Movement and defence :
In a four link :
Flamedash>>arcane surge lvl6>>second wind>>Steelskin

+immune to reflect if you don't use armageddon Brand
+immune to elemental ailment as long as golem stay alive
+golem auto respawn
+most of your time is spent dodging

-max dps takes a bit of time to be reached with scorching ray
-clear is meh even if Armageddon brand is enought for it
-the build peaks at 1.4 million dps wich is not enought for bossing or Maven encouter

Why no Elemental Equilibrium or Elemental Overload?
Not close to my path for the first one and you could use the second one if you chose to not follow the cluster jewel road but i think that Armageddon brand doesn't enought crit chance to proc it constantly.

Is it really a starter?
Yes and a budget one as the wand I have is quite good and i made it with alt/aug/reg for the 2 fire mod and the int then messed with it in harvest for the rest. Most of my gear is self crafted/looted (from ritual or random harvest craft). I only brought the helmet, shield and jewels.

Is the cluster jewel mantatory?
No you can just use regular Jewel instead and maybe pick up EO but you could use a cluster with Cooked Alive like in the Pob because it is the best IMO.

Flask recommendation?
Use the one in the PoB they cover all of my problem, maybe change the freeze immune for move speed but I use it as an emmergency in case all golem are dead. Cinderswallow takes care of our mana problem while mapping and is an overall good flask thanks to the ignite of Armageddon Brand.

What are your achievement with this build?
I can do T16 maps with no problem, I have killed 4 of the conqueror because I am bad and I probably lack a bit of defence to tank the last phase "DIE" beam. I've killed all the guardian deathless for the first time but I have yet to try Shaper for the first time. Can't do breachlord because we don't kill things fast enought to get to them. Maven 10 boss fights are hard as hell and I have yet to choose the correct boss to do it.

Do you die often?
Yes

Can the build be upgraded?
Yes, gear-wise I would need a +1 fire and fire dot multi wand, an amulet with +1 intel woulf be good, an explodey chest would help a lot for clearing, otherwise I don't have enought knowledge to know what i could do to improve it and I am open to suggestion and advices.