My myth pet peeve: There's something wrong with making a tied quilt.
I love tied quilts!
As for paper dulling scissors, I've suspected that was something adults made up to keep their kids from borrowing (and misplacing) the sewing scissors. As far as I can tell, as long as the scissors don't get a nick in them, they're fine.
I use my rotary blade for cutting paper all the time. It's going to wear out and need replacing eventually, so I don't see what it matters if it gets worn on fabric or worn on paper.