In general if one waits until fermentation stops to transfer to secondary, how many more points will the SG go down by after a couple weeks in the secondary? or should I expect the SG to remain about the same?
It should probably drop by 0-2 points, although it may have finished fermenting, as you transfer to secondary you stir the yeast up a bit and so it will probably start feeding if there are any sugars left that it can break down.