I personally would find it interesting to expand upon the red magic aspect of the class, while mechanically adding to the existing proc management system.
For example: a 2s cast spell that consumes both "fire ready" and "stone ready", has 350 potency, and generates 6-8 white and black mana. Maybe call it "magma". Pair it with a 5s cast time spell that can only be cast after "magma", has 400 potency and generates 8-10 white and black mana. Maybe call it "squall", as if to combine aero and thunder. Unsure if it should proc anything.
Being able to cast those spells represent a higher dps increase for using both your procs, though ideally it wouldn't be enough of a dps increase to justify spamming jolt until you have both procs. This would encourage proc fishing even more than we already do, and also prevent the awkward "too much good rng" situations where you're swimming in procs and can't make good use of your impact.
Additionally, there's room for design in other aspects of the class. At risk of going into a rant, I'm not going to go too far into what I've dreamed up for weaponskills, but a single example would be a weaponskill that branches off of enchanted zwerchhau and applies a 60 second dot. Maybe. Having mentioned DoTs, could just include "verBlizzard" and "verWater" as seperate dots. Nothing too fancy, but duration would have to be fairly high, as even just 20s duration means 1/4 of your casts become dots.
I think my take on this would be that there's a crapton of room for improvement in design complexity, and that I would be disappointed if there were no changes made. But I haven't personally gone into the math implications of any changes, so I can't say if my ideas are particularly good.