If your shoulder has been painful for years you’ve probably started moving your shoulder in a funny way, maybe limiting the motion of the joint to avoid the pain. Using less ROM makes the joint less mobile.
These arm circles against a tiny band(1:00) are a good way to restore the shoulder joint.
After that they do some internal and external rotation moves that you’ve seen 1 million times. When you do those motios, make sure your arm moves smooth. If the motion is " herky jerky" or your arm “rachets” jumping a few inches at a time you gotta smooth that motion out.
At :30 they show a 1 arm pullover motion to build shoulder stability, work the serratus and some arm muscle you never heard of, and take pressure off the bicep. Then at 1:30 a band uppercut to rehab the bicep and practice shoulder extension.
The band circles, pullover and band uppercuts are good. I did those moves 3-4 times a week for a month or so before I was pain free.
For a pressing exercise, you gotta try Landmine Presses. I know they look like some kind of incline bench, upper chest motion, but they are a Great shoulder move. There is weight/ resistance but your not 100% supporting the weight. For whatever reason this let’s you get great, full range shoulder motion and allows your scapula to move around freely so you don’t get AC joint pain.
For the lateral raises, go stand in front of the mirror and watch your shoulder super close. When you make the lateral raise motion Look at what happens. If your front delt or your trap contracts first, you’re doing it wrong. Try again, looking at your medial delt and make sure its doing the work. Put the fingertips of your other hand on the mid delt, or do whatever you have to do to connect with that muscle. Take as much time as it takes to figure that shit out.