Composites
Hi Jim,
As has been pointed out, you're kind of screwed. Definitely should have asked first. But, since we can't unring that bell.....
There are special scissors for kevlar if you need to cut the stuff in the future.
Also has been pointed out you may have compromised the integrity of the bond by using Kevlar as it doesn't bond well to dissimilar materials. If there is a way to remove it, I would. This may involve using a sanding drum on a high speed air tool. If you aren't interested in removing the Kevlar, the next option would be to add a couple of layers of glass cloth over the Kevlar. The Kevlar needs to be completely covered, it is not sandable.
Regarding carbon, it will not give you any significant advantage for use on the wind screen. Carbon is great where you want strength without flexing. Carbon in thin laminations is very brittle and splinters easily. It only becomes strong and durable with thickness. You can sandwich it between glass layers to give strength and save some weight.
I remember reading that someone was talking about making Carbon wheel pants. They would be very light but durability would be nearly non existent. Same with empennage tips. Not to mention, expensive.