I'm assuming your 400 to 500 arrows are carbon. I'm not saying you can't shoot carbon from a wood bow but it is a mismatch to me.
It doesn't matter whether a bow is center shot or not any bow can be accurate with properly spined arrows. Trying to get any arrow to shoot well is the wrong way to go. IMO I know nothing about carbon arrows. Buy a set of wood shafts spined 5# to 10# less than your draw weight and tune them to the bow.
I've made hunting weight selfbows that were as narrow as 3/4" at the arrow pass. As long as the fades and handle area are thick enough there shouldn't be a problem. Make the transition between handle and fade a smooth transition, thickness and width, rounding all the corners and edges and if you want a shelf, add one made from wood(a golf tee split in half), antler leather or cork.
Generally when a person cuts a shelf into the handle/fade area they make abrupt cuts that weaken the bow in an area that gets the most strain because of the leverage of the limbs.