FWIW, the 3 2 1 times are for 225, not 250. The extra 25 degrees makes a big difference. I agree that "2" is generally too much time in the foil. In fact, I feel foil is useful for beginners but is unnecessary once you understand the dynamics of cooking tender ribs. However, if you don't foil, it's a good idea to brine.
You can certainly cook ribs over direct heat on a charcoal or gas grill. Allow about an 90 minutes for spares, most gas grills, at the lowest flame setting. About 300 - 325 deg as measured by a button. With direct heat, it's unnecessary to remove the membrane during prep because it will burn off. You can help this along by scoring the membrane. Start bone side down. Cook with the hood down, turning every thirty minutes or so. Sprtiz with a non-flammable mop on the turn. Keep sugar amounts down in rubs and mop, because sugar WILL burn. Use the "bend test" to determine if ribs are done. When they are, glaze the ribs with your dipping sauce and allow a further 5 minutes per side, for the last 10 minutes of the cook. For the glaze, start meat side down, and finish bone side down.
What were we talking about?
Klose Steak Grill with Swing Set
Backwoods Fatboy with DigiQ II