Reset slides interactions on last slide

What do you mean by 'buttons with audio included in it', please?

You can attach object audio to any object, also to buttons. But you can also trigger an audio clip with the Success action by using the Play Audio command. It is difficult to uderstand you r question. Why would all the buttons suddenly play their sound or action when revisiting the slide? Actions can only be triggered when the button is clicked.

Resetting a slide: depends on what has to be reset. If you use states, and don't check off the option to retain states, the multistate object will be reset automatically. If you made an object visible with an action, you'll have to hide it again using an action triggered with On Enter slide event.