Some people still use bumpers, and you will want them once they start rolling around and banging against the sides of the crib. A lot of people hang the quilts on the wall or drape them for decoration.
We just bought bottom sheets without the set for this reason! Once DD transitions to a toddler bed (maybe sooner, she still seems to get tangled in blankets right now, though) we'll just let her pick out a bedding set.
The jury is still out on if bumpers can actually be contributed to SIDS from what I've read. Yes, the quilts can't be used for infants but can be used as a throw in your rocking chair, a wall hanging, or once they get bigger and can use blankets. Most sets I;ve looked at include bumper, quilt. sheet, and skirt so if you don't mind using a bumper and can make other use of the quilt you can get your use out of it. It's certainly not mandatory though.
Re: Bedding Question