So yeah I was wondering what the opinions and arguments for and against modding weapons with either %Dmg or +Crit or +Ignite Attack

are there even any maths perhaps?

so far I've heard crit is the highest DPS option but why? why not ignite strength and/or damage?

my opinion is phase + crit=soft shelled mobs + increased damage chance

I did lightning build then i respecced to fire

Dont bother with lightning.

Get a +1 arc on a claw for when you need it, otherwise to 10/10 hellfire and flameshards

7 dual focus
10 arcane shield

hellfire owns tempest royally for AOE spells.

You'll have enough skills left for something else useful like bone spear 10 which is insane dmg itself

on the crit versus damage mods versus ignite issue, it kinda depends what you want to do with it.

Effects are really hard to proc on bosses if they are above you in level, and you can kill mobs faster in other ways than igniting them.

So if you want to use ignite or poison on bosses, you'll need dual 4 slot foci with 200+ proc mods in them plus any skill or expertise in elemental str to even get a decent proc rate.

If you're killing mobs just use nice elemntal damage mods. With shield pen maxed for demon and spectrals if you're doing class heavy runs.