Buzz, no. I think Buzz is more of an old man than they let on. Metamucil, colostomy bags etc. Don has a tendancy to drink too much when he's alone or bored. With Janet and now his new radio show, it's nothing to be concerned with.
Mike is a fucking drunk. He's shown up to work. There was even an episode of MOM that did the first segment with Mike drunk off his ass, went to a break and came back with Best Of.