what do you mean "bottom and top"? one semicircle cut at most on the areola edge should do it, if he's leaving two scars anywhere else, it's not needed. is this guy experienced in gyne, or is his idea of experience he's done a couple of other guys before?
it can grow back again, but the more that comes out, the less likely it is. if your hormones are more or less level, no prob, it's if they start fluctuating again you get a little risk of it coming back, but that's not that often.