“Rubbing shoulders with” almost always has the sense of associating with people who are somehow successful or famous. I go to this conference because I feel that it’s good for my career. it allows me to rub shoulders with decision makers from all the important companies in the field. When my wife joined the board of the charity, she didn’t know she would be rubbing shoulders with Seattle’s old money. That’s been a very interesting experience for her.

No, it doesn't sound natural. :D It would mean that you physically like rubbing shoulders with someone, since you're talking about one specific person. I think the phrase is only used when referring to a group of people that stand out for some reason be it fame, fortune, or intellect. I don't really see it as negative phrase, but in saying that, it's just not common enough for me to have a clear sense of how it's used the majority of the time. Here are a couple of examples of it used positively: - After the conference, a lucky few were invited backstage, where they got to rub shoulders with some of the top minds in the tech industry. As you can see, I have only been able to come up with one example, so you're probably right :D I think most of the time it does have a negative connotation. Although, strictly speaking, it can be used in a positive sense.

You would use it with a certain group of people, not a single person. The idea is that you are walking through a crowd of these people, very closely, and chatting to them. As a result, your shoulders rub with theirs. I've just entered "I like rubbing shoulders with" as a quote into google, and you certainly find plenty of positive answers.