Re Seat Sandal descent:
On early attempts we used to go straight down to the lay-by next to the Achille Ratti hut (by the bus stop) and then go straight over the A591 and up a gully on Steel Fell immediately below the summit. Although this line is the shortest on the map and could be quicker than the usual way further to the north we found it too steep on the way down and I wouldn't recommend it, especially not in the dark.