Need help to make a good build (Scion - Caster - EE)

Hey,

I'm currently playing in the 1 month Flashback league (SC). My character is a spell casting Scion, that tries to use Elemental Equilibrium and curses to scale the spell damage.

My skill gems and links:

3L: Firestorm + Concentrated Effect + Increased Duration (+1 to all gems from Lifesprig)

4L: Lightning Tendrils + Spell Totem + Lightning Penetration + Added Lightning

Auras: Purity of Fire + Clarity

Curses: Elemental Weakness

Playstyle

Put down the Lightning Tendril Totem to trigger EE and possibly shock enemies. Cast long duration Firestorm and curses in between if needed.

My build so far - LvL 56
Passive skill tree build

Concerns

Triggering EE works like a charm. Tendrils and Firestorm hit in frequent succession.
However I'm worried about:

- Will damage scale into maps well enough without crit? I'm planning to use dual curses to further increase the damage.

- Will I survive as a life based character? I'm only used to playing life based characters, will I be able to get enough defenses from my current tree?

- How do i spend the next 20 skill points?

I'm thankful for any ideas you guys might have!

Firestorm works fine as non-crit build.
Life based is also a viable choice.

I would avoid aoe nodes in the tree. Reason: You have a fixed number of fireballs raining down. The smaller the area the higher the chance that all fireballs will hit a target. If you increase the area, some will just drop where no one is standing. In case you took those nodes for lightning tendrils, switch to arc. Works probably even better for triggering EE.

[1.3]KuteKitteh's Firestorm Warlord - Insanely durable and affordable, Atziri viable on a 4L might be helpful for planning your tree.