Is there a way to add a non-breaking space ( ), an en space ( ) or an em space ( ) without having to switch to source editing?
Special characters on VisualEditor
Subject is already being discussed on Phabricator.
Not yet, although see https://phabricator.wikimedia.org/T134382 as it may eventually happen. What is your use case for the last two? TY.
To be honest, I can't really think of any use to en and em space as of now, but thanks for pointing that phabricator link!