New main Radial or tape drive...?
Oh, forgot about question 2.
I always avoid any deviations from the designed sail shapes. The modern yacht designer has a very sophisticated tool set to use while designing a boat. They can usually very acurately predict and compensate for balance in a vessel. Once you begin to deviate, a little longer in the foot, bigger roach in the main, all these things will change the centers of effort on the boat.
You should not make major changes in your sails without consulting the designer of your boat. If they cannot be reached, a qualified naval archetect should be retained. I know of folks who have chased their boats balance after making seemingly minor adjustments. Mess with your CE and you may end up with lee helm.
Have your sails made to the deigned specs, but if you make changes, make sure you look at the boat as a system and make sure you are aware of all the effects of your changes. Changes should be made to correct a problem or effect a positive result in vessal handling. In the need to "Just go faster" many un unwitting sailor has made the wrong move.