The thorns wouldn't help your penetration much, I guess, but I bet they'd leave a great blood trail! Sure would tear up your 3d targets, though. And probably not do your hand much good, even with that steel bow glove you wear. Better just remove 'em.
But seriously...those are nice looking shafts! I don't see a lot of wild rose around here that's big enough. I hear they make really nice arrows. Red ossier is pretty easy to spot in the winter along creek bottoms, at least around here. So if you had it in the area, I'd guess you'd know it. Anyway, I'm impressed with how straight you've got those, and I hope they don't check on you. Good work so far!