Every time someone explains why you were wrong, you become very defensive and lash out, often by saying others are all worked up. But nobody is, except you. We couldn't care less, we're just explaining why you're wrong.

And again, you weren't being evil. You were being chaotic. Good rp for an imperial means you don't want to break the law in the first place. It's not an option. Thinking you can get away with it means you're thinking that killing someone is more important than your character's ethos, and, not just that, his imperial oath, both of which are supposed to be who he is, not just an inconvenience to getting other things. Order is the thing you want. You, the player, did something that the character wouldn't, because the character wants order, not chaos.

Same goes for a lawful paladin. You think they don't want to kill the evil in the city? Doing so doesn't make them "good", it makes them "chaotic".