I don't know much about wsl but they probably want to develop on headless linux why still being able to use GUI Emacs.

Don't. Its a black hole and your ROI will be negative.

What does this book offer over the built-in manuals?

Good job. One big downside I see is that you can't see existing tags when creating a new note, one doesn't want to remember all tag names each time you create a note.

Which points to the grep command, so what really needs to be customize is grep-command no?

After disabling evil, the emacs "leader" key is C-c instead of Space.

You have to use emacs regexps though, Both complement each other.

mg is the successor to microemacs.

And evil.

What don't you like about vscode?

Org mode is freaking awesome. Initially when I started with emacs for coding I was still using Notion and a few other organization/note apps. I'm fully Org and Org-Roam now and not only do I vastly prefer it, I now own all my data, and it is all in plaintext.

How do yo deal with mobile?

vscode is king here, even jetbrains feels crap compare to it.

Best solution is emacs on the remote server and get used to the 20ms which doesn't sound bad IMO, but maybe you have less tolerance than me ;)

There's no current solution in emacs for what you want and there could never be so I wouldn't wait for it.