I don't roll the batting, it hangs down and I usually just kick it under the machine when it gets in the way.
Your backing should be 4" extra all the way around, 8" long and 8" wider than the top. This gives you room to 1)attach to the leaders so you don't run over things and 2) test tension on the sides. When you advance the quilt, you change the tension slightly, and when you change bobbins, things change. This gives you room to make sure everything is ok before you have to frog (rippit, rippit) a whole row. This also gives you some breathing room in the event that things get a little wonky.
I have one set of zippers with leaders, and 4 sets of just zippers. I sew my back directly onto the zippers. You can get a really good price on the long zippers on e-bay.
I've seen the side clam thing. I just take once of the clamps that came with my machine, and clamp to a skirt hanger. It gives me two clamps to connect to the quilt, and they both have the same tension. I don't always use the side clamps. It depends on the quilt!