Foam roller didn't do anything for my shoulders. It was the shoulder mobility drills, which I also do every time I work out, even if I'm not particularly targeting my "shoulders" that really fixed me up. As part of my warm up I do...
Side lying windmills
Thoracic extension and rotation
Then I do 1-5 of the movements in this article http://www.dieselcrew.com/5-minute-shou ... -exercises
I will occaisonally throw in a scap wall slide as well.
Adding that to my warm up has made all the difference in being able to OH press.
My pain was all in the front, where the anterior deltoid kind of ties into the clavicle? You'd have to ask somebody who knows anatomy well to tell you what the actual muscle insertions were. Shoulder is a complicated spot.
As to roller speed: I usually pass over the length of the muscle I'm rolling at a moderate speed unless I feel a tender spot. Then I kind of linger over the tender spot, sometimes rolling back and forth right over it, sometimes just letting the roller press into it. It took a couple of weeks for the acute pain developed when doing that to go away.