Base Build, where to from here? (Suggestions please)

Here's my current Build

As you can see its pretty open, as in I'm not locked to any specific skills or items. Nearly everything I've taken is defensive. I've been relying on %physical from strength for the majority of my dps so far.

My next port of call is Inner Focus via this route.

For the future of my character I don't really have anything set in stone, I've tried not to be locked into anything, apart from going 2H, and with the Dex/Int nodes I have I can use nearly any weapon.

What I'm thinking of doing after Inner Force is specing in such a way as to max my dmg for a specific skill. The two I'm tossing up between is Ground Slam and Lightning Strike, my goal for each is huge area effect while maxing the damage.
Lightning Strike I really like because it has the potential to scale really well (Iron Grip 2x %more gems) and its ranged capability, though I feel to make the most of it I'd have to use Chain(50% less dmg) and Iron Grip. To move the above spec into something quite effctive requires another 12 points.
Ground Slam has worked quite well for me so far but doesn't have the scaling or range of Lightning Strike, the plus is it requires less passives (9 instead of 12) for increased AoE, which leaves more for weapon/2h passives.

As I was putting this all together a few questions occured regarding the way the Lightning Strike projectiles worked. To make things easier, this is how I think LS works:
Main hit dmg = X dmg. (Not worried about types atm.)
Projectile dmg = .7*X*(IronGripStrMod)
So Everything is applied to the initial strike then the projectiles take thier dmg from that, are modded by the 70% effectiveness, then anything that effects projectile damage

Do they benefit from the %reduced Stun threshold that came from the original hit?

How does the Chain 50% less dmg effect things, it it applied only on the initial hit/swing or the projectiles only?

Static Blows, +%chance to shock, how does that work? since as I understand shock is applied on any lightning dmg over 1.1% of health http://en.pathofexilewiki.com/wiki/Shock#Shock

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Basically thats the builds I'm planing. Complete at 82-85 Points. Any additional points will be either 2h mods or weapon mods, possibly maybe some more health since they are really close depending on how things go.