This is the PERFECT spice mix, and the best way to season the meat. Trimming the membrane off is crucial, and actually not that hard to do with a flat boning knife if you insert it parallel to the rib and directly over it. Once you get the first few done, you can grab the membrane and just tear it off the rest.
But for the preparation, I prefer to SMOKE the ribs Southern-style on a Weber instead of doing them in the oven. The key to this is that you put all the coals in a pile on one side of the grill, then all the meat at the far opposite side. Add the soaked hickory chips and the seasoned meat (no sauce yet) and close the lid quickly, close down the top and bottom vents to about 1/4 open, and leave it that way for an hour. Then, add more soaked chips (adjust the vents if needed) and start basting the meat with the barbeque sauce once every 15 minutes for another hour. Close the lid as quickly as possible every time, as the chips will want to flare up and you want to try to avoid that.
I've done this at least a dozen times now, and it comes out perfect every time, with the crunchy carmelized sauce on the edges and the meat very tender and juicy.