Look into stuff associate with this:
http://www.chekinstitute.com/
They're good for that kind of stuff. Also, yea! Shoulders! Super-easy to make things worse with improper technique! For instance, if you're doing push ups, keeping your elbows in, and your arms parallel with your body GREATLY reduced stress in your shoulders. And they're usually harder, which is an added bonus. And just 'cause you posted the pullupy video, when you do the deadhang before you pull up, it's really better if you always keep your shoulders engaged, don't let them rise up: As you're sitting at your desk right now, raise your arms straight up into the air. You see how you probably automatically lifted your shoulders so that they go right up to your ears? That's not great for them when your body weight is dangling from them, it puts A LOT of stress on the joint, rather than on the muscles that hold the joint. Now, with your arms straight up again, engage your shoulders, pulling them back down to shoulder-height (instead of ear-height) while keeping your arms in the air. That's where you REALLY want to be any time you're dangling to help protect them. And also don't forget to keep your core engaged while doing all of that stuff. Yay.