1. Usefulness of Rebellion could be improved by making it non-offensive.
As opposed to rioting, a rebellion could be plotted in secret

It would serve as a battle starter for Reavers or something we
could start brewing while a barbarian prepares their battlecry.
2. Black Hole would be cooler if instead of being just another area
attack spell it would create an object similar to a wanderer vortex
that would deal damage over multiple rounds. Maybe upkeeping the
black hole would cost energy & sp each round and require standing
still. Finally, it should be powerful enough to be useful, while
being costly enough to be affordable only on very special occasions.