I always imagined Simu making two spell choices for the 750 slot for the multitude of different “classes” in each profession too add individuality.. In this case necromancers and demon summoners for sorcerers. While Major Summoning would be great for the latter, I think this would be great for the necromancy side.

Using Neverwinter Nights 2 examples we could add abit of resistance or immunities to mind/cold/electrial magic/paralysis/poison/disease and increase to necromancy to your list. The ability to cast no spells sounds harsh. How about the added consequences of not to be healed ( no blood and tissue! ) and the ability of CERTAIN spells like demon summoning and most of minor spirital spell circle. Iam sure the ingredients should be made for both to semi rare. So I guess my idea of the necro differs from yours as mine would be cast as more of a shield to proect you from certain death rather then a after death utility.