I practice this style. Don't even try to learn this without an instructor. In the unlikely event you find the points you will likely do yourself serious damage.
They do work on most people and those shown are not even the most effective/dangerous. Learning the points is not difficult with the right recourses but some require specific angles to work, others must be struck and others are deep inside the neck. You have to push your finger into the neck to reach them.
Also in a real fight these are useful but not at all sufficient. No one will stand still and let you poke them. You need a system of techniques that set up the opertunities to use these. And lots of sparring practice.
If you want to take something from Shorinji Kempo that is useful, learn the meiuchi. Its a strike with the fingers in a whip like action to the eyes or groin. Easy to learn easy to incorperate into other styles and very effective.