So instead of shaving the outside of the flywheel, it would (in theory) best to take the material from the center point out to a few mm short of the edge. Or drill holes around it front the center out. But you can't really do that without compromising the integrity of the flywheel right? That's why most lightened flywheels are just skimmed across the face .0xx" and the outer side/ring is left alone?
No... your theory is wrong. do not take it off near the center. You want to take all of the weight off the outside of the flywheel. The problem is the outside shell of the flywheel is not very thick. I have seen the damage done when a flywheel comes apart. The outside of the flywheel was machined too thin and it takes the left side of the engine off when it explodes.