I would definitely change your string & peep. If you are using a brass nock and eliminators, get rid of them and go with a loop or tied in nock & eliminator.

Also with your very short arrows, you should probably go w/ feathers..this will pick you up a bit of speed and add some forgiveness (and arrow spine will remain sufficient for the bow arrow/combo you have cited). But the main reason is because with that short of an arrow and vanes you likely will have serious FOC problems. It may not show up w/ field points, but fixed blade broadheads or long ferrule mechs will likely get squirrelly on you.

after those changes, I'd leave the bow alone.

As for the feathers ...

I would gather E-wolf is using "natural" turkey feathers (i.e. from wild turkeys).

Feathers do have more drag. They will slow down quicker. But it really depends on how much helical you put on them. With a heavy helical like I use they will slow down much quicker than the same helical with vanes even as close as 30 yards (Was testing this last weekend as a matter of fact). However in a more moderate helical or just an offset, there is little practical difference out to 40 or 50 yards.