All good suggestions. Single leg stuff, especially with a long stance, will help as well. Helps grow and condition the adductors and hits the glutes and hamstrings...push off heel.
Keep in mind that the glutes are still the primary movers...
You hips being sort of sore like they are now is what I expected. It's why is suggested the low rep sets. Not because I thought you'd really stay conserviative but because you would maintain proper technique and not have tremendous amounts of DOMS from it. With the higher rep sets you could likely have been more sore from having lifted LESS weight..who wants that?
