I have been completing my backhand by letting my racket follow through over my shoulder. That follow through can shorten my stroke. If I end my swing high enough so that my arms are almost straight instead of bending my elbows as the racket goes over my shoulder, the ball goes higher.

I have trouble getting my service toss in front of me. It seems to end up over my head most of the time. If I lean forward as I toss, whaddya know, the ball goes forward too. Ever see Pete Sampras serve? Any further forward and he would fall forward.