blightcaster also has call lightning and call lightning storm and wail of the banshee (good luck with necronancy DC, it's fine while leveling, but at end game if yours is not a DC caster...).
I have huge issues hitting mobs with thorn lance, try it. all other thorn spells often miss targets in the area of effect because you are throwing thorns (don't expect the behaviour of a fireball).
black dragon bolt has 5.5 seconds cooldown, imagine to wait so much time before hitting a second target (you are not able to keep fully dotted 2 targets because it lasts only 8 seconds)
Only acid well is good on a blughtcaster (conjuration fortitude save, good luck rising enough conjuration AND evocation dc
).
then tou have to decide to strip acid immunity or getting more acid spell caster levels.
You listed so many spells but you know better than me that you can specialize in only 1 or 2 things.