Sorry for having routed the discussion away (into whether to use player names in commands or not).
The main point I initially wanted to raise was that such a totally generic player renaming method would be very easy to abuse; I for one would be very upset if I find my character renamed on a server; not to mention that it could be renamed to something offensive (or that I consider offensive) or rude or...
I am sure that @Minotorious will never do this, as well as most of the server owners we know and respect. But we can also be pretty sure that sooner or later someone will rename some (or all?) the characters on a server in a censurable way.
If the problem are blanks in the name (as well as other problematic characters, like possibly quotes or apostrophe), I would understand an automatic procedure which replaces these characters in player names with underscores (or another 'jolly' character). Such a procedure could be documented and run 'blindly'.
But the name of my character is my choice (within the rules), and not anybody else's.