Hi all - When we introduce keyboard shortcuts, we do not intend to override OS commands. We consider this recent addition of alt+left/right a bug and will be fixing it in the 4/16 release. The fix will ensure that when you are editing a text box, this command does not override the OS command.
As far as we know, these are the only commands that we've introduced that override the OS commands. If you have experienced any other issues, please let us know through a customer care ticket and we will get those addressed as well.