Your changes are overloaded for no reason. Instant cast frags stunned before, it's not coming back and frags certainly doesn't need resource return over 5s. It's half cost when instant, which is the only time you'd use it, meaning any use of the ability is a spike in damage and sustain, since it costs less than a normal spammable. So it's fine the way it is..

If your purpose was to give sorcs more sustain, this is the wrong direction. Stamina Sorc already has pretty good sustain. Magicka Sorc can get a tweak somewhere else in the kit.

My suggestion would be to combine some of the passives which fixes more than 1 issue. The 20% Stam/hp Regen passive with the 10% mag Regen passive, but make it 20% too. Main reason being, many passives for Sorc are wasted to have their effects as their own unique passives, leaving no room for actual tank or healer related passives, which are very lack luster. On Templar for example, you have cost reduction for ultimates and abilities in the same passive. We have 2 passives, just because their different numbers.

A passive for cost reduction after blocking, ult cost reduction, skill cost reduction. Why does this require 3 passives when sets like Acrobat handle the cost reduction across the board. A passive just to return Magicka when a pet dies. 2 passives for Regen.. it's ridiculous. The useful passives are pretty strong though. No doubt.

Crystal blast on the other hand could use some work, stacking spammables to get an explosion proc is a cool idea. Once again, you then took it too far. Everything causes off balance now, it doesn't need it, it certainly doesn't need a dot and resource return. Edit: and a heal?! That's way too much. You need to pick and choose, it can't do everything.

Frag Stun would be good, they won't revet it tho. Robbing that in 2017 led to the 2018 debarcle of rune cage etc, had loads of knock on effects, leaves us with poor CC choice, slot management etc.

But they won't revert. .