The side with the glue should feel rougher, stickier, look slightly different. Cut a small sample and try it.
As for the other, I think it said good to 4 inches for quilting - so do what you like. Leave enough extra so you can finish as desired. If you have scrap fabric and enough of the batting, experiment. Make a sandwich and try traditional binding.
I've had iron on stabilizer that wasn't too good, so I just used it as sew in and treated it appropriately. Same with iron on batting for jackets. I'd just quilt it down.