Mjølner build questions

I'm playing a Mjølner Scion who is on act 4 merciless atm and it's going very well. I know it's not the "real" endgame, but so far she can facetank anything and packs die like i'm serious sam. She's life and armor based, although my plan was LL or CI because i realized i didn't have enough good gear to go that way yet, tho i may respec later if/when i do.

So to mt questions:

1. I'm using double arc with iron will in my mjølner atm, because i don't feel i can afford a voll's devotion. while packs die pretty much instantly, bosses take a while to kill. It's not a huge issue because i'm mainly trying to be a tank anyway, but i'm wondering if that is where discharge comes in. Does discharge provide a lot more dps against bosses for example?

2. If i did want to invest some passive points or stats from gear into dps (provided i feel i'm tanky enough), what would be the way to go? Spell damage for the arcs? Attack speed for more procs? Physical damage for more molten strike dmg seems like a poor investment to me.

3. I've hear tell of people who use lightning strike instead of molten strike, that could fit quite well since my arcs and herald of thunder already do lightning damage. With lightning strike i could throw in wrath aura and conductivity curse since pretty much all my damage would be lightning. Would this be a good idea, and if so would you use any other support gems for lightning strike than for molten strike?

I play a budget (no volls, no 6L) life based mjolnir build that is dual curse and is highly effective.

arc and discharge are supported by a pseudo-5 link...

Controlled Destruction (Gem) - Iron Will(Repentance gloves) - Life Leech (Warlord's) - Lightning Pen (Conductivity)

This build has so much strength that Repentance gloves are insane. They provide us with 809% increased spell damage for our arc and discharge. Since we are not crit, controlled destruction is a great 'more' multiplier for spell damage. Warlord's gives us life leech and endurance charges. Conductivity allows us to shock without criting, and reduces enemies resistances.

Lightning strike is better vs packs, but molten strike is better vs bosses.

You could easily use a 4L for lightning strike - multistrike - blood magic - faster attacks if you wanted to test it out.

Here's my gear and tree if you're interested.

Gear


Tree

Thanks for your input.

I haven't thought of using controlled destruction with romira's. should mean one rarely loses ones power charges to anything, but discharge. Not using romira's atm since i don't have voll's and i worry my powercharges will just dissipate on their own with a crit. tho i have to admit i have a poor understanding of the interactions of discharge and charges, probably since i've never used it.

Repentace seem awesome.

Daresso's Defiance also seems like an interesting choice especially since i'm going iron reflexes and i also use devoto's like you. Just using a 5L astral plate atm. decent, but could be changed