You can't do either of those things exclusively in the Flowchart.
To change the audio in just one timeline, open the Timeline viewer, click on the audio track and press "Delete". Add the new audio to the timeline.
Or, if you want to change the audio clip globally, select the clip you want to replace in the Project panel and go to File>Replace Asset. Point Encore to the new Audio file.
For the slideshow, select the object in the Flowchart that links to the slideshow. Then use the Properties panel to delete the link to the slideshow. The slideshow will return to the orphan area of the Flowchart.
Jeff do you know how I can learn how to make my own custom menu in photoshop? I notice there seems to be some important codes on layers when I open one of Encores Library menu's in photoshop. I am trying to learn how to make my own. Do you know any tutiorials that would help me learn this?
And one more thing Jeff, if I can ask you one more question. The slides in the slidshow where the time line is. Sometimes there is a thin green line on the top of each image and sometimes there is a RED thin line. WHat does all that mean?