Fairly New to POE, LF Skill Tree Feedback

So, as the title says, I'm pretty new to POE. I've followed some builds in the past, but I've been recently trying to come up with my own.
The build would be based around Smite, so the things I'm looking for are:
Lightning damage, Shock, Area Damage, and Crit
I plan on supporting Smite with Multistrike, Elemental Damage with Attacks, Ancestral Call, Added Lightning Damage, and Lightning Penetration. Other gems I'm probably going to use are Herald of Thunder and Wrath. And I feel like this is the perfect build for Mjölner.
I've seen lots of other Smite builds that use Herald of Purity, but I don't really want minions in this build... just tons of lightning damage.

Here's the tree I've come up with so far. www.poeurl.com/b8MG
Please let me know if it's lacking anything or what could be done better. I haven't really done any endgame content, so I really don't know how many defensive passives are needed.

If you are aiming for a melee oriented build without a lot of ranged spells used you should consider spending some more points in HP/Armor imo.