It sounds like some of your reaction might be yours; your coworker sounds annoying but you sound extremely annoyed, like you might have been similar or wanted to be similar in thinking in your younger years but been squashed by someone?

When a coworker bothers me, I look at myself and my reaction to see what I can learn. So what if they think they are better? They either are or are not, based on what they do. Sometimes other people thinking they are better makes me anxious because I know I'm the best and it's a bit threatening?

Your worrying about his getting himself fired if he doesn't "shut his trap" makes me think of my reaction sometimes to trucks sneaking on the parkway where no trucks are allowed. I use to get all incensed until I realize the signs weren't put there for me or by me and didn't have anything to do with the "rights" of car drivers, were there for the road's sake! The trucks hurt the road, it's not built to take the heavier traffic. So, it's not about the truck drivers versus car drivers at all and I'm not that road's police person in the first place.

Maybe the higher ups see him as "exciting" and full of energy and ideas? Watch the interaction between him and others and see if you can figure out how you can become like someone who doesn't mind this guy? I use to listen to my coworker talk to her mother on the phone; she was so caring and patient and I was a wreck talking to my own difficult mother. I started practicing being like her on the phone and things went much better in phone conversations with my mom and me!