Crafting skill

lightning only need to knock out the inquisitors of their invisibility and almost useless up to 20 lvl.

Its not true, it very helpful for ur team to kill ice witches, remember u cant kill them with fireball.

Remember there is a block, and every normal wizzard use it to block lightnings.
Lightning:
base skill power 207/230/274 we will take 3 upgrade (274)
then lets take ~2500 mastery points as 20 lvl approximate value for fire mage.
So we have some sort of mathematical form of lightning skill:
274*2,5=685HP
so its 685 hp per lightning, each costs 7 classpoints.
Ice witch has 70% blockpower, and we have 205 damage per lightning for 7CP. How many lightnings do u need to kill fullgeared icewitch with full HP runes? Calcuate and think whether it makes sense to spend so much class points.

There is no need to use lightning against ice if u can use magic silence to steal her mana, or lift her when she freezes.
Fire mage is not supposed to be a main DD, there is other characters that must kill. Sister of fire (at the time of the last patch) is just a support class. U will understand that in some time, maybe.

Most of the eu ice witches dont block at that time and it has huge range, 2nd more'valuable' skill than flaming hail ( everybody can block it). So u can put those skill from flaming hail to lightning.

And fire witches usually camp and not stand in the middle, and dont have to kill, just damage them.

Most EU witches sux then.

U just do not know how to throw them so that no one has seen them and cant block. Hail deals more damage than lightning if u know how to use it.