How do I set new Manjaro global theming settings?

Hello everyone! I’m very new to the forums and am here for a question:
How do I go about setting globally (in GDM and all newly created or old users);

  • adw-gtk3 as the legacy GTK theme instead of adw-gtk3-dark
  • morewaita as the icon theme (only for gtk apps)
  • the new adwaita cursors and fonts
  • setting the QT theme like so that, these apps use dark themes in dark mode and vice versa.

and have this configuration not be lost after updates.

Also, after all of this is done: should I remove the papirus-maia-icons and bibata-cursors? If so, how can I safely do it?

I’d be grateful for any support. Thank you very much!

… pretty generic answer:

GDM appearance can be set by the (an) admin user via some menu - or by editing the display-manager (GDM) configuration file directly.

The themes within a particular session / user account can be set from within that session.
Individually, by each user to their liking.
The admin could do that as well for all accounts - but that’s a bit more involved.

It’s usually a per user account setting.
And:
there is no way to do it globally, for all already existing accounts, at once easily.

For newly created ones it’s a different story - /etc/skel/* would be the place, I guess.

No, you should not.
You probably could - but there is no harm in keeping the option for the users to choose it.
Unless storage space is really tight.

There is no easy GUI way to do all that.
Not only not in Gnome.