Lightning Witch help.

Hello all!
i need your opinions and advises on my Lightning witch (Currently level 37)

this is my Passive Tree:



i am using Arc as main spell with Lightning penetration and Increased Lightning damage.

For Auras i am using Clarity and will use Disc when i get it.

i also use the Curse that reduces lightning resistance of enemies (i forgot the name >.<).

i am wondering if i should get the Reduced Mana Reserved Nodes and Increase Aura Effectiveness since i am starting to suffer some mana problems or should i just focus on Mana Regen nodes?

as you can see from my build i am trying to get as much ES as possible but i need to know if i should pick the HP nodes or is there a passive node that converts all of my ES into HP because i saw alot of witches without ES and don't know if that is possible or just a bug, and should i also get Resistances or will i be strong enough that i can burst down mobs before they reach me?
also any ideas on when should i start going Damage in the passive tree or should i just focus on staying alive?

Also i want to ask about the Vaal Gems.. i have no idea what they are and i think i have both Clarity and Arc Corrupted and wondering if i should use them or not?

My gear is bad because i am a new player and can't really afford anything yet.

I could really use any advise on my Passive Skill Tree before it is too late to fix anything.

Thank you guys so much for your time and sorry for my english!

unspec out of those crit nodes, spec into EB.

Clarity lvl 20 + aura effect and reduced aura reservation will grant you infinite mana + AA

For a cheap build i would head down to iron reflexes and run a grace aura

@HarukaTeno yes it's OP but also quite gear dependant (empower lvl 3 and higher)

but if you have the curreny i would go FoxTactics build

EDIT: quick skill tree i made http://www.pathofexile.com/passive-skill-tree/AAAAAgMBAuMHYwelCPQRUBGWFSAW8xcvGYUZhhmKGmwajxzcHwIkPCSqJjwnqSmlKk0snCzpL28vnTbFNuk74UZxSVFJskp9TipV1lYtVytabVuvZOdnoG0Zb55wu3NTdhF5A36vf8aApIIQgh6DCYd2i3qTJ5u1na6io6cIpyunXKxHrH-0DMBUwbTB88M6ykrYJNkT2wvdDd-w4vfjauTs5oHrLPba-tL7CfzF

You might want to reconsider changing your build to using HP and then taking the eldritch battery keystone that converts all ES to mana. Then you won't have any mana issues.