Caster/CI build (my first scion)

Hi I'm pretty new to POE and I'm looking for some criticism/advice on my scion build. My highest level char is my scion on 53 so I'm not too sure how well the build will do in the late game:

http://www.pathofexile.com/passive-skill-tree/AAAAAgAACGeTOr0nGDxX4fllIcOQ1rfW21ktqLGQgwkspjdmNAqm6zeD6rq0DJMnHNw4G3_GL50W8yY8wcWIQvIdLL-GrhXX14ZWY-wYw22io8HzbRktH4-mRKtVriycSbIC4welghDfsCj66-64kzLREdtFR7UEXcbd82BtRtftIOFzi4wFWzEBpwiPRh0U6XNMNSjF87760uOC5wvesHB9qZUaMlFgT32AVmaecU2az0NjtzFY9Z3E-ehBh7c-xq48LcT2d2I9DySL98F8u548gW9N2Ix2aHTaYpSgDPckJTWAiLpXyQFvPI6ESDvh4venK4t6

So far I've been relying on arc as my main source of damage with supports gems reducing lightning res and boosting cast speed.

I'm pretty squishy right now because I opted to go + spell damage route and have only now just started to pick up the defensive passives. Is this a viable build and do you think it will start to get more survivable once I am able to pick up the passives in the templar tree?

Any gear tips? -> right now I've just been trying to balance armour, energy shield and health (until I make the transition to CI when I have more of the energy shield passives).

Thanks!