Hi eldrin,

presumably alternate titles for movies are used to help associate a movie title with a folder/file name

Yes, they are both useful to aid in searching and also as a reference for things like working or abbreviated titles.

the actual naming that the client application (e.g. XBMC) does is only done according to the Original Title or the Translated English title that is returned from themoviedb

That's entirely up to the client, but yes, that is generally how most clients do it.

Thanks for clarifying Travis.