I only use a rotary cutter to cut out ribbing or small items; otherwise a scissors - much more precise.
I have had my pattern weights for about 30 years and love them. They are like giant silver ring washers - well about 4 inches in diameter for the largest, but I have them in various sizes. They have little grips on the bottom to stop them moving. The grips are about four 1/8 inch pin heads sticking out of the bottom. I can’t find any pattern weights with grips these days and I need a few more.