It was probably Samsung DeX.
Samsung is helping Google to develop a similar thing for Android.
You can run the browser without any issues, use ssh with JuiceSSH and have the terminal. Running vim on there might be an option but another editor that is not a TUI might be more troublesome.
I also had a Zen Phone (if that's what you meant) and it definitely played audio while charging.
All the phones that I have had with a audio jack would charge and play audio without any issues, ranging from a lot of different Samsung Galaxy to Wiko phones.
Those numbers don't seem high, at all, for me.
Typing would probably cause a refresh more often than every second and even if it's delayed to be once, every second, it's still only 11 days.
And it's not only the Airpods that are very popular.
All of them are popular and most of the people don't face this issues.
I have some Sony XM3 and although the touch interface is weird you get used to it and I never face issues with connection as stated.
I don't know about this specific tablet but tablets that can be used with pens usually feature palm rejection, and you can rest your hand while writing without any issues.