I think theres a lot of stuff that would be good to have in stealth but a lot of the problem I think is just healing in stealth. I think the mechanics would be a lot more interesting if they allowed you to use buffs in stealth but supressed self healing cast after entering stealth, self healing in general in stealth, or healing in general (probably would need some testing to see which would balance nicely).
For example Id love to see casting hurricane or dark deal in stealth or defensive rune. Some things not casting in stealth are really just inconvenient like defensive rune and dont actually affect combat situations other than being annoying.