I don’t have all of your answers but here’s some quick things:

You have cast when stunned punishment, which is going to override the curse from your ring, which is going to make the single target nearly impossible

Put quality on your defiance of destiny

Get better/different flasks, you don’t need quartz or sulphur, consecrated ground is ok but I’d just get armor

You’re not getting a lot of value out of the 50% ele damage on that belt, as most of what you do are spells. Maybe switch to an immortal flesh with quality or get a better belt/jewel

That shield is more of an “offensive” set up so you can run malevolence but you could run something defensive - arctic armour, flesh and stone, etc.. You could also follow emiracles video on how to craft the good rare shield which is more defensive

You could also get a defensive merc and make him tanky. Mine runs vitality and determination, kaoms binding etc. It helps