Generally HRT can result in mood swings, etc., at first but if you're already having those it'll probably balance them out a bit. Most Ts are unstable so it has the effect of mellowing them out a bit(though still generally pretty far from making them "stable", that's only something that happens with therapy, time and good friends).
I'm no doctor, not even close, but as I understand the G-spot is not unlike the male prostate gland. I don't know much about the different procedures that take a he to a she, but if the prostate remained might a freshly minted gal have a G-spot of sorts? *shruggables*