I understand how the screen shake, flashes, hit sparks and other effects might not appeal to everyone...Thanks for reminding me. I'll add options to toggle those effects in the next update!
For the CPU vs CPU, yes, it still needs a rework. As mentioned in the dev log update, it was a carry over from the previous AI, which was meant for fighting against humans. I'll change it up and hopefully we can get more exciting fights in spectator mode.