The part of the Beholder's eye where beauty resides is separate from the part that he uses to see, so as long as you didn't take out the whole eye, you shouldn't have any issues.

Honestly, I don't think this one really requires a creative twist. Just let him become a dictator, they don't usually lead long or happy lives anyway.

I figured dolphins were in that sweet spot where they were smart enough to be curious about exploring the external world, but not so smart that I'd have to worry about them realizing I was manipulating them and revolting against me the way humans might. I did consider crows and parrots as alternative options, but I didn't want to use animals that small because I didn't want to have to worry about the loss of knowledge every time one of the smarter ones gets eaten by a predator. In retrospect, elephants might actually have been a better starting choice... wish I'd thought of that before they went nearly extinct.