Unless you're going to spend the time to sand them smooth and then seal them, you're simply going to waste $$ on nocks, fletching, and points because you're not going to be able to keep those dowels straight enough for shooting.

Plus, as you alluded, unless you're going to be shooting them out of a really light bow (<20#) you may be running the risk of having them come apart unless you have a spine measuring jig to make sure those dowels can stand up to the draw weight of your bow.