Yes that sounds like a starting place.
Yes add the neck tissue mobs in too.

Yes, the first rib acts like a pump and can impact this.
Which elements are you seeing the most improvement with?
Have you hit traps or delts?
Identifying what around the shoulder is tight and working with those aspects is an important part.
It can mean hitting the same areas a few different ways.
Jill Miller has some great quick fix videos  that address the neck, shoulder,  upper back, and a stress relief video.
You can receive a free quick fix here others are available for a small fee.