I find that your butt is supposed to be in a different place over the saddle in or out of the saddle. Without going into the specific details, Sounds to me like you are experimenting with your butt too far backwards over the bottom bracket.
With your dimensions, it sounds like your torso is actually shorter than average. Im 6ft3 with 34.4inch inseam and I am already 1% more on the leggy side than average.