I use 4 different strokes, depending on the situation. One that works really well in most every situation is the first one I learned, which Tor Lowry calls the jab stroke. Because it is a short stroke with a short bridge it tends to eliminate errors that can be induced by a long stroke. It also works well as a fallback in a match if you are tired or having issues getting a good long stroke. Some top players use it exclusively, some use it on short finesse shots.
Click
here to see a vid by Tor Lowry that covers the jab stroke starting at 3:08. He shows the pendulum stroke, which is what you are using in your video in the first 30 seconds of the video, but doesn't really instruct on it. While he says this vid is for advanced players only, he is mainly talking about the slip stroke, from :30-3:08.
Here are some ideas for drilling the long straight in shot...
A vid by Max Eberle - click
here - shows 2 variations of a drill. Note his suggestion of using the seam between the cushion and the table as a reference line for warming up your stroke.
I use a different variation of his second drill in which I put a donut on the foot string and one on the head string such that they line up into a corner pocket at a diagonal. The CB sits on the head string donut and the OB on the foot string donut. I start out by pocketing the ball in the corner using a firm hit stop shot with the objective of CB going neither left or right after impact. Nobody is perfect though, so I will declare success if it only slightly moves.
After making that several times I start gradually ratcheting up the force, staying with the objective of minimal post impact CB movement. My goal is to get up to the same force that I use when I break, and because I am using it for that end, I am using my breaking stick as well. For break practice, it is a lot faster than racking every time and once I am dialed in, then I will try a few racks.
Another good drill that will help straighten out your stroke is to line up all 15 balls in a line between the side pockets. Place the CB on the head string such that you shoot half of the 15 into one corner and the rest into the other corner, all as stop shots. Once you can shoot all 15 without missing, increase the force a notch. Rinse and repeat.