Either one is OK. The left and right only come into play if you are shooting off the shelf. Some say the right helical will spin ina manner that will cause the tip to tighten instead of loosen but a little string wax on the threads would prevent tip rotation.

The goofy arrow flight can also be caused by a shooting form issue too. You may want to have someone stand off to the side and behind you to watch the arrow also. It may just be the way you see the arrow from your perspective.

How is Broadhead flight at that distance? Does it hit where you aim also like the FP's? Do your BH's hit the same as your FP's?