RE: what vanes do you shoot?
Being as you mention feathers as an option I guess you mean what type of fletching we use. Feathers are feathers. Vanes are plastic. That being said I prefer feathers, but occasionally I shoot vanes. When I do I use Duravane 4" LP 400's.
For orientation? Helical, always. Haven't shot a straight fletch in over 30 years.