If you're going for full lowpoly, then it doesn't really matter, does it ? Just do an a-pose with bent elbows while you work, then pose afterward. The pockets could be just hand overlapping the pants... Or you could make pants with actual pockets.
Hem of the jacket ?? I think we can pull that part up slightly after we bake the lowpoly (maybe with a bit of baked in wrinkles). Maybe we can move a few verticies of the pants when we put the hand inside ? Think that would look weird ?