He's 100% correct on tightening, and torquing the control arms at ride height position. What I never thought of, but learned over on the gmt400 forum (from Schurkey) is that it's OK to ignore that warning if you're using the polyurethane bushings, and it makes total sense. The rubber bushings are bonded to the metal shell. Polyurethane are not.
Unrelated but back to your to-do list, absolutely do not fear recovering the lower seat cushions. Probably the easiest seat work to do. My only advice is to be super super careful working with it as the edges of the sheetmetal seat frame are VERY VERY SHARP. You will cut yourself. Just take care to not cut yourself too badly.
Oh, and if you have power seats, don't cut the hole in the cover to the size of the panel. Cut just the smallest necessary opening, because the aftermarket cover won't have the stiffening plastic rail sewn inside that catches around the edge of the seat frame. Look at your old cover in that area when you remove it and you'll see exactly what I mean.
Richard