The lines on the 8x10 comes from lack of use (the build up of chemicals on the rollers. Kodak always tells me to print 50+ prints and the lines go away (it will also get better as the holiday season is here). The singed edges are coming from the paper being exposed. Change the roll.
At my store, I'm the Photo Lab assistant. I fill in 80% of the time while our GSA or GSTL disappears. It's really annoying because since I have supervisor functions, they are happy to take advantage of me.