The last couple of quilts I did were backed with fleece. I debated about using batting or not, and ended up without. I think they're just the right weight without it.
I spray-basted and had no issues with the quilting. I just used a fairly large quilting pattern all over to begin with, then filled in the areas where I wanted heavier quilting.
While fleece does stretch, it's also quite forgiving, and as TonnieLoree said, if you put the fleece on the bottom when doing the base allover pattern, the feeddogs work it in nicely without wrinkles.