As far as using a split piece for an arrow, my uncle gave me a primitive x-bow from Vietnam that shoots bolts that are just splits of boo. They weren't even rounded. They fit into a groove along the top of the x-bow. Some even had a curve to them in order to shoot around corners I was told
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. It looked like the points were heat treated to harden the sharpened boo.
I don't see why you couldn't laminate several layers and get a decent arrow. Were you talking flat laminates or the pentagon/hexagon shape? The latter might be something interesting. It would have to preform remarkably to make all the extra work worthwhile.