We need to see some unbraced, braced, and full draw photos to tell you the most.
I use four .001 tapered lams in all my bows, so I doubt you used too much taper.
Yes, many times longer bows will seem to be lighter. You need to have acess to a scale. You can use any bathroom scale for this.
What kind of longbow do you want a recipe for? They vary bunches in profile, and willl require different stack dimensions. How long is your riser? How thin are your fades? Many questions can be answered with some good photos.