Anon, I slightly tilt the turkey so that the legs/thighs drain slightly over the white meat (if that makes sense – hard to explain really) so that the juices run down that way. Keeps it nice and moist.
I never have done that, but it actually makes sense, because the dark meat is fattier (and therefore juicier) than the white meat, so it probably would “baste” the white meat to do that.
As to the “carcass” thing, well that’s what the bones are called. And there are always just enough tiny bits of chicken on the carcass, plus the bones themselves, to make a really great soup. Smart cooks everywhere have known this for centuries, and always use the leftover boens to make a hearty broth( which in turn, can be used as a base for many other fleishig dishes).