If you " just cut them" and they are green... I don't know if you will be able to get them dry by opening day. Oct. 15th.
Spin is not as important with tapered shafts as it is with pallallell shafts. However, It is still somewhat important. Spin can be tested with your hands. Just flex the shaft in your hands several times until you get the feel for it then flex a shaft of known spine and compare the two.
You can make a simple spine tester with a two pound (I think) weight and two 2 x 4 boards. You can eye ball them in quite well this way.
If you are hoping to hunt this year with these arrows.. I just happen to know where a bundle of dry river cane is.
David