I took a class from Carol Doak several years ago and she really is a wealth of information. I recently took her class on Craftsy and if I remember correctly she said that paper would not dull your scissors. I have always used the little quarter seam ruler, I think it's add a quarter with a lip that goes against the folded paper, then you us your rotary cutter to cut long the ruler getting an exact 1/4". It works.

I buy Fiskar children's scissors at back to school sales each year. They are great for thread snipping and if dropped won't hurt them at all. I have a basket of Fiskar children scissors for all ages for my grands to use. They cut paper with little effort and the kids don't get frustrated. We like the soft handle ones the best.

Paper is not made like it use to be made. It will not harm your scissors.