If i have a toon i like with how the UI is how can i make sure it carries on to all characters? Including the ones on other realms. Talking everything like addon settings, adjustments, interface etc.
Most addons have the profile setting, if possible you might be able to try making changes to the 'default' profile. That way if you make a change to one, it carries over? YMMV.
Copy the contents of your character folder to existing characters that you wish to share the same settings.
WTF > Account > AccountName > RealmName > CharacterName
Once you copy this and log the new character, most of the UI should be the same. You will likely need to go ingame to: Esc > Interface > Addons and load your main characters profile for a few select addons that are not behaving.