All these special imperial powers only really show their sickness when they're stacked on a class that does not normally receive them. I.e. Emperor.

Healer with healing curse? Eh. Shaman with healing curse? More dangerous, but still eh. Necromancer with healing curse? Suddenly we have a problem. Same thing with piercing gaze, imperial tactics, et al. Maybe you could consider reducing their effectiveness for Emperors? I know I cringed at the thought of an Emperor with all four.