I think Japanese males don't use watashi in casual conversations but females use it.
If males use it in casual conversations, it may make one sounds overly stiff and aloof as you say.
is often used in Japanese sports community. They has strict age hierarchy in regards to using polite manners, it is called . So includes the meaning of humility. It is rarely used in formal but there are some people using in casual conversations. They are probably .
In addition, also means the second person(that is to say, "you") in Osaka.