Thread art may not be needed but it doesn't hurt, The neoprene gets wet and slippery and slimy if you ask me. That's what I hate about it. Matter of taste though. I'm sure some love it.
whatever the dia of the blank is at the seat add just over 1/8" for the CT.
Like Toby said feels great , better ballance and easier on your wrist. I especially like it on conventionals