How do you apply panel settings to all users?
And when editing the applications menu, how do you apply modifications or edits to all users? I may need this in the feature when doing things like making KDE/Kubuntu-based Linux distros.
The most common way is to deploy a custom theme. You can inherit from an existing theme and only override the elements you want to change.
You can have a look at what other distros do by looking at their source code.
I meant I wanted to apply panel settings and edited menu items to all users. Not apply a theme to everyone.
There are tools like KDE migrant and konsave that let you copy settings between users but if you are really making a distro, that isn’t the way to do it.
If I also wanted to apply to all new users from now on, then how?
You can add the settings files you want to use to /etc/skel and then they will be copied to new users.