At what point did Kirk have an alcohol problem? Getting in a bar fight doesn't make someone an alcoholic.
You keep calling him an imbecile? What exactly
did he do that makes you think that? Yes, he was a bit obnoxious. And yes, he was a bit arrogant. He's practically a kid! Destroying Nero's ship? That's your evidence? Nero was a genocidal mass-murderer guilty of destroying an entire planet and nearly destroying another. He gave Nero the chance to surrender. Nero didn't take it. Under the circumstances, Nero was not worth trying to save.