amend that with "a good subset of Emacs editing functionality that works almost everywhere (^p, ^b, ^f, ^n, ^k, ^y, ^e, ^a, ^t, ....)"

The use of Control is the single-most annoying behavior of all these surface-only reskins.

gtk-key-theme-name=emacs at ~/.gtk-2.0 and simillary ~/.config/gtk3.0/settings.ini after the [settings] block.

Honest question: what does that do to application shortcuts? Say, printing. On macOS, cmd-p will open the print dialog. In Gnome (and in Windows I assume) ctrl-p does the same. With the theme above, what happen on ctrl-p and where's the keyboard short for, say, print?

IDK, I think the shortcuts open on dialogs and widgets.

?? I don't know what that means, but AFAICT, the keybindings you suggested does not actually solve the problem with the use of Control. I tried to make that as painfully obviously as possible with the Print shortcut; control-p can't both be previous-line and a shortcut for print.