It still places stress on your tunica so yes. The tunica is tougher to stretch than the ligs are but every little bit helps and you are already sitting around with your dick in your hands while doing the other stretches so I would say why not do them as well!
Stretching as best as you can in a variety of directions helps to make sure that all parts of the tunica and the different ligs get worked in a more even way.
Yes, I use the shotgun approach and hit it from all angles. Don't forget about the helicopters/rotors. They work great to keep your cock limber and your flaccids pumped.