Hi
It would be a very good feature to add to Publisher.
Sometimes you need to force a line ending in order to make the text look better.
In past softwares, before the advent of Quark and In Design etc, you could make a soft line ending by using a two key return that would end the line where you want to end it but also would not be active if the line length changed. The problem at present with all these various softwares is that you only have a paragraph style not a single line style.
You could introduce cmd+return which would be a clever addition and something that the other softwares do not have.
Thanks
Martin