As a new user I find it very cumbersome to change the audio and the subtitle of a movie.
Press the button to get the OSD
Press right 4 times.
Press the select button.
Press right once for audio or twice for subtitle
Press the select button
Press down once(?) to get to the audio language
Press right to get to the arrow so you can change the audio language
Press select to cycle to the correct language.

Same for the subtitle selection.

That's at least 11 remote control actions to change the audio language/subtitle for a movie.

I'd recommend it would be possible to:
Cycle through the audio streams by pressing the 'A' button on the remote.
Cycle through the available subtitles by pressing the 'S' button on the remote. And one of the options should obviously be "Off".