RE: too much helical????
Helix obviously stabilizes the arrow by means of spin. Ironically, this spin can work against you if you have too much. Spin creates drag, which is what stabilizes the arrow, but too much spin also slows your arrow down dramatically.
But it's a moot point, really. I don't think w/ any commercially available fletching jig on the market you would hurt yourself. With your drop away rest, go for it.