I suppose, you want to swap English titles for German titles and vice versa.
Normally, the labels contain secondary information like type information, subtitles, etc. pertaining to a thought. And sometimes they are just blank. If you would have the functionally to swap node titles and node labels all at once, you would need to duplicate a lot of information, because there are many thoughts, i.e. usernames ('deutschblitz'), proper names of persons ('Bill Haley'), and organizations ('NATO', 'UNO'), where a translation doesn't make sense. For all these you would need to duplicate titles and labels. Looking at your 'Liederschatz' website I can imagine, why you would want such a feature. But then, what about three or four or ... languages? I have a hard time to figure out a use case where I would want to have a 1:1 translation of all the thoughts in a brain.
Reinhard, TB 10.0.48.0, WIN 10
Quality is the result of attention paid to details.