Just two things boys.
Start them off at 1 second GCD. We’re more or less time wizards at this point. Why are we slow to the point that it makes doing our rotation based around Radiant Spark (which we’re balanced around for some reason) awful?
Let Arcane Charges juice Arcane Explosion like it does Arcane Blast. If we’re gonna have to fish for procs to do the big dakka for AoE, we might as well have it do some damage and a 1 second GCD will make proc fishing faster.