Upswept ends will definately catch more wind, how much usually came from experimenting. From what I understand the reason was historically to quiet the boat, would slowly enter and exit waves where a more blunt end would tend to fall off waves making a splash, bad when you're stalking prey.

Skin will generally follow the curves, no issues, the gunwales define the curves more than the line from the bow tip to the cockpit.

Bill H.