> Things got even worse when Apple "reinvented" the Play/Pause button in High Sierra.
Actually, this was introduced midway through macOS Sierra; https://developer.apple.com/documentation/mediaplayer is available in macOS 10.12.1+.
> Buttons rock. It's always faster to tap, not slide.
If you press Fn, the slider will go away and the "normal" function buttons will appear.
> I want to have instant access to Finder, anywhere. Default Touch Bar can't do that. Weird.
Why is this weird? Finder is always in the Dock for every user.
> E.g., the eyedropper tool, to take the hex color code from the screen.
/Application/Utilities/Digital Color Meter.app
> Standard Touch Bar will never support the most useful feature — to display the name of track playing.
Slide out Notification Center.
> Would be cool to display the name of the YouTube video on the Touch Bar, right?
See above.
> You have a script running once in 20 seconds, and praying it won't overload the CPU.
Don't do this. Use AppleScript to watch for changes, instead of polling.
> I decided to steal this feature and make the "coffee break" button. It locks the laptop and switches the screen off.
Press the power button.
Not offense, and I'm sure you enjoy your setup, but I really think it would do you well to learn a bit more about why your computer was designed that way rather than writing a rant online and spending time making it "just right".
EDIT: it looks like this comment is pretty controversial, since it's flip-flopping between ±5 points rapidly. Let me give a more detailed response.
Personally, I don't have a computer with a Touch Bar. I have, however, used one a borrowed one for a couple days. Personally, I would be fine switching (there are other issues with the MacBook Pro that are preventing me, but that's a story for another day).
I don't use the function keys that often, so I don't feel as if I'm "losing out" on them. Many of the supposed grievances that I normally hear are easily solvable ("oh, I didn't know I could control the volume slider without lifting my finger", "I didn't know I could add sleep to the Touch Bar"). Really, I think the main issue with the Touch Bar is people view it as a second screen rather than an extra set of controls as it's supposed to be. The Touch Bar is meant as a place to have surface extra controls that would be nice to have at your fingertips; what it is not is a place to show you data or be a Dock or menu bar or Notification Center or Activity Monitor. Why? Because you're not always looking down at it. There's no point putting any significant information there.
That being said, Touch Bar is not perfect, of course. It's a nice idea, but it could be improved if it provided more tactile feedback (e.g. haptic feedback, some sort of dynamic change in texture). And given that it's new, Apple's guidelines, while good, may end up changing as real-world usage influences them. Overall, though, I feel that much of the Touch Bar criticism is based on knee-jerk reactions or issues that are not difficult to resolve. Yes, there are some deeper issues, as I've outlined above, but I think the concept as a whole is interesting.