I think it's fine if people with
personality traits they didn't
appreciate can alter themselves
consciously without seeming
fake, being
uncomfortable, or trying way too hard. Of course, that's a tall order.
As for what a real personality is, and being able to distinguish consciously fabricated aspects from previously existing ones, I think someone's 'real personality' is either that which they're exuding at the moment, or the sum of every noticably different expression they've ever produced. Either way, the 'real personality' is constantly changing.
I mean, what was your personality like 10 years ago? Was that you? It was then, but it certainly isn't now.
I don't think changing your personality yourself is any more weird or wrong than letting it change 'naturally' as it would by normal social interaction; that is to say, there's nothing wrong with it, as long as you're comfortable. In addition, this 'real personality' I'm defining is merely a noumenal entity, fictional even, not something anyone actually thinks about when they're talking to people.
I realized a while ago that, at least among younger people with others they don't know too well (which are the ones we're likely to be changing ourselves for anyway), many don't even contemplate what a person used to be like - they just take what they see as if it were coming from a new person altogether. Maybe I'm completely retarded and terribly unobservant; maybe what I mean to say is that people judge others based on what they've seen even before they speak again.
Yeah, I think personality types will definitely run away from themselves if so forced by society, or if one feels that society is forcing the changes. Yeah, it's possible that a personality is composed in a large part of reactionary revolts against what one perceives as unsuccessful social ventures, but it's probably not likely - usually when someone changes and the change results in success, they simply live with the assimilation happily, and don't look back. Looking at it one way, in this aspect, it's kind of unimportant to be worried about this stuff, but as an insufferable introverted contemplator myself, I empathize, and I'm inclined to say that just about anything that you think about instead of remaining unconscious of makes you better for it.
Final note: If people are worried about losing aspects of their former selves, they had better stop living. If people are worried about doing this consciously, even when they hate what they're ridding themselves of, they can always keep a journal, or merely remember what they used to be like, or talk to others about how they used to be.