I have a Singer 201, stretched to 18", on my Hint frame. It has a dial mounted to the top of the machine to adjust the speed. I've heard of people using dimmer switches to control speed, but I'd speak to the machine's manufacturer about that first, especially if your machine is digital. And have an electrician do the installation. You do not want to mess with any wiring.
Velcro is a good way to go. I just purchased some Red Snappers used from a friend, have yet to try them out. There are Mondo Clips, also. Pinning just seems archaic to me now, lol.