For the credits you can select "backgrounds" and open the jpeg. Then you create another menu and use the "credits background" as background. Then you rightclick the credits button in menu 1 and link it to menu 2.

For audio options you have to make another menu with 2 buttons, 1 for each audio track. You rightclick the "options" button and link it to the audio selection menu. You can rightclick the audio track buttons and link them to the correct audio track.

Click "VTS 2" one time to select it and press the delete button on your keyboard.