First off sorry for the month old thread necro

My cinderblade is only level 23ish. I have been assigning stats as follows, (STR)2=WIS. (example: if i have 150 STR I want 75 wis )
Priority of itemization on gear as follows:
Crit chance > Crit bonus > Melee Bonus > STR > VIT > WIS > Any other weapon or elemental damage additions
Weapons:
Dual wield the slowest ( for base damage ) correctly itemized one handers I can find.
Talent/skill build (currently)
1 point burning arc ( cheap for spamability )
Max lava field ( Boss killing debuff )
1 point Thermal screen ( Used when going into melee boss )
Maxing all melee passives asap
21 Cinderblade main attribute ( haven't read much on the 30 point skills so I stopped at 21 for the moment )
This build has had no issues killing everything so far, I rarely use health pots. Due to the higher than base WIS, I have had no issues spamming Burning Arc for extended periods. I am aware that these conditions may change as I get higher in levels.
Ok, now that you understand where My toon is at, here's the Questions I have....
1) Why are most advocating the use of a 2 handed weapon ?
I agree that it hits (per attack) harder but Burning Arc strikes with both weapons if dual wielding. A 2 hander would have to hit twice as hard as a 1 hander to be equal in unmitigated damage output. I have yet to see a equivalent level 2hander have twice the base damage. Most I see sit at about 130% to 150% the base damage of a equivalent 1 hander. That's a 50% loss compared to two 1handers.
Further more, if the damage was equal or even a bit better with a 2hander you'd still lose the itemization/stats on the second weapon. Also you'd have to expend precious stat points or gear itemization to boost DEX just to equip them ( polearms / scythes ).
I'm not saying I'm right.. I see many well thought out replies on these boards advocating 2handed use ( Scot in particular ). I'm just wondering what I am missing.
So what am I missing here?
2) When is an ideal time to start raising/maxing Burning Arc and/or investing in Burning Swath ( it's passive Boost ) ?
I am hesitant to do this as the mana costs will raise considerably. On the flip side, the positives are greater damage per usage and I have extra Wis in my build currently to try and account for it's increasing costs.
Any opinions on this would be great as I am stumped on when to start pumping it up and how much to raise it