Two Questions

Two questions have really been on my mind the past couple of days.

First, you see many baseball players who bat lefty but throw righty but you never see the opposite (bats righty and throws lefty). Why is that? I mean you have plenty of guys who throw lefty and are switch hitters but it seems none who purely hit right handed. I understand why you'd want to be a switch hitter instead but doesn't that logic extend to players who throw righty but hits lefty? How come there aren't any players who hit righty but throw lefty?

Secondly, a blonde is a blonde, a brunette is a brunette, a red head is a red head but what do you call a woman with black hair? You don't call her a "black" and you don't call her a "black head". Seriously - what do you call her?