I'm 5ft 4 ish. I'm a size 12 and I was a 36F. I got reduced and am now a big C.
I am much happier than I was though in my heart of hearts, I wish I could be a little bit smaller as I don't think my height and my chest size are still quite in the right proportion (although my bf thinks differently!)
That said, I am on the contraceptive injection which has definately added weight so if/when I come off that, I'll probably get a bit smaller in the breast area. also, I could probably do a bit more exercise than I do which wouldn't hurt either.
Re the scars, showing though tops, I guess anything is possible though mine definately don't. I also wear a bra, the underwire of which sits on top of the scar which would stop that, even if the scar was raised.
I think doctors probably do try and 'scare' you a bit, because some people go in to cosmetic surgery thinking it's a small inconvenience - like when people go on cosmentic holidays thimking they'll be right as rain after the 2 week break. It can take months and months before you're functioning normally again - for me, it was at least 8 before pressure could be applied as before, before doing exercise was as comfortable as it had been and even then, the scars were still apparent. They fade a bit over time but never go completely.
BTW, after you've first had it done, I'd suggest investing in a few sports bra's to wear instead of normal ones as the underwire rub against the scars and itches like crazy!