I don't think you have an extension cord trouble, but you should make sure that it is a heavy-gauge cord to avoid drops in power to the CS.
BB Ribs usually are less fatty and the time you smoked them sounds right to me, but if you want the meat to fall off the bone it sounds like you should have left them in a little longer. Usually, the foiling process will contribute to your desired effect, so I am surprised you didn't obtain what you wanted.
Did the meat on the end shrink some so the ends of the bone were exposed a quarter to a half an inch? That is a good sign that ribs are cooking well. I also try to twist the rib bones. If they move easily, they are ready to eat! As Smokin' says, "They're done when they're done."
Because your brisket only weighed 5 lbs, it sounds like it was a flat. They typically don't have as much fat as a packer cut that has the deckle and a fat cap on top. The fat in the deckle prevents the dryness problem you experienced. Many folks place bacon on top of the flat to keep it more moist. When you smoke a flat, you will need to keep a close watch on the internal temperature. They usually don't need the full 2 hours per pound.
Keep good notes and you will soon be able to produce exactly what you want!