My homeboy Cell doesn't get enough love around here. He is my favorite villain in the whole franchise. I really liked his lack of ambition, it offers a nice change compared to the usual overlord you get to see in most stories. Seriously, why the hell would you like to run the world, sounds like a pain in the ass if you ask me.
When he was stronger than everyone and could have destroyed the world he held a tournament and goaded a kid into killing him.
So no. No. And also no.
Yeah, but why would he does that? He wanted to prove to everyone and himself that he was the ultimate warrior, and that nobody could surpass his strength. Destroying the world would have kinda ruined the point, since he wouldn't have seen the full potential of the Z team. I think he was an intelligent villain in the way that his action always matched his objective contrary to Frieza for example who could have killed everyone pretty easily when he knew he couldn't use the Dragon Ball anymore but he didn't for no real reason.
"There are 28 big cities, and I'll randomly destroy 1 each year. That means that if you're super lucky, you'll get to live 28 years before I destroy you!". When you were a kid and you put yourself in that situation, it was SCARY as hell. Cell? "If there's not anyone strong enough, I'll destroy the planet and then. . .hmm. . .I guess I'll go to other planets and do the same?". Weak. Really weak.
If I was a kid, I would shit my pants in both cases. lol