I followed your conversation and also contatcted Damien ( original GHOST_cocoa writer ) for
send us a helping hand.
I must say i also don´t think this is especially an OSX issue now, due i never had any problems
handling unicode in OSX else.
Must be a special case in Blender.
Also all debug prints show up right outputs in several places.
Again i like to point out that for example "öäüÖÄÜ" is only shown
wrong in outliner ( "öäüOAU") but when exported to an external script
( luxblend here ), pby output was right sending it as "öäüÖÄÜ".
I formerly got some misinformation on the state of usability in other OS, so this seems a more general problem.
Thus i don´t see atm a needed change for OSX in GHOST rather than checking outliner and perhaps other modules.