Hi.
I would like to ask you if it is possible to set these back, play, forward keys to work also with movist. Every time I'm watching movie in movist and try to use these, nothing happens in Movist but iTunes launch instead.
Yes. What you need to do is get a tool that will force those keys to default as the function key, rather than as a media key.
FunctionFlip is great for this.
Next what you need to do is force key bindings for the controls you want. Since Movist doesn't appear to support changing the key bindings from within the app, you'll need to do this through
System Preferences > Keyboard > Keyboard Shortcuts. Click the + button, find Movist in the Applications drop-down menu (you may have to search for it), add the exact title of the function you want to re-assign (ex: Play Speed Faster) and then press the function key you want bound under Keyboard Shortcut (ex: F9). This tip didn't work for me with the Play/Pause menu item… it appears to be hard set to spacebar, but most everything else should work.
EDIT: I should also add that use of these rebound these keys is only good while Movist is open. Unlike with iTunes with the keys set as normal media keys, you can't use these to control Movist if it is playing in the background. There's no way around that, afaik.