I never, ever thought about renaming body parts. I mostly tend to ignore the parts I have that I shouldn't have, and try to think about them as little as possible. And when pushed, I usually go as far as saying "down there" or "it" or something.
To give something a name, in my mind, acknowledges it's existance. And I would rather not acknowledge it exists as a part of me. It's something that doesn't fit... something that doesn't tally with who I am and the image I have of myself in my mind. And I'm not sure that using either masculine or feminine terminology would make me feel like it was mine.
As for my chest, I guess I do still use that term. I don't have breasts yet, so I can't associate that name with something that isn't there, it's too much of a leap. But 'chest' is, I think, pretty neutral anyway, so it isn't that big a problem for me. And I might still end up calling it my chest even when my breasts are fully developed.
Overall, though, I am a woman in every way that matters to me. The way I think, feel, love etc. And my body is only a small part of who I am; one which can, and will be altered to fit with who I am. As such it doesn't play a large role in my sense of self-identity. So I haven't formed any great attachment to, or association with it.