^ Well, that's true, but it's particularly the fact the he treats everyone else with respect, apart from the person who deserves it most. That is a big black mark on his character.
Don't really have a problem with it, they treat each other the same. Merlin calls him names, occasionally does things to make him hurt himself. Sure it's an exaggerated level but it basically seems to be friendly banter between them.
That's the most interesting point-would anyone else of Merlin's standing in the world be allowed to insult Arthur as he does? Maybe Gwen but that'd be it...hell the Knights wouldn't be allowed to talk back to Arthur the way Merlin does. That, in effect, Arthur's best friend is a serving boy, and the woman he loves a serving girl, tells you more about Arthur's nature than any pot throwing or name calling.
Yeah, if Uther saw/heard how Merlin treated Arthur I'm sure he would be in the stocks or in prison, if not put to death.