how do I display ALL the articles from a prior issue?
At this point you can´t do that. You will need a custom hack for this.
Is there a way to display more than four articles on the cover page of an issue?
Yes, of course. Edit your issue and go to Design tab. There you can set how rows and columns for vertical and horizontal articles. Just set this as you need.
2) Is there a way to display the table of contents of an entire issue?
You can use the current article module.
Please let me know if you have more questions about this.
Best regards,
Author