I've frequently used serger thread in my serger to overcast the raw edges on denim when I'm making jeans. I've never had a problem with breakage or tangling in the machine. I even grabbed some last week for basting some handwork. Make a little sample and try to pull the layers apart. There are needles made for denim-- I'm not sure of any differences to a quilting needle.
Last week, I pulled out some Maxilock serger thread for my first FMQ because I had a lighter color in it than the Connecting Threads brand that I had ordered. I had to rig up a cone holder and spool holder for my machine