He's Dead Jim Documentation
As of this point, there aren't any options. Simply install the plugin, activate it, and sit back and enjoy the nerdiness.
No screenshots are available yet. When they are, they will appear on the plugin's screenshots page on wordpress.org.
What happens if "Hello Dolly" is still activated?
Normally, "He's Dead, Jim" will output its text where "Hello Dolly" does. If "Hello Dolly" is activated, "He's Dead Jim" will output its text to the left of "Hello Dolly"'s output.
What happens if "Make It So" is also activated?
"He's Dead, Jim" will appear in a box to the left of the screen, and "Make It So" will appear in a box to the right of that.
It is possible to customize the plugin's appearance using a child theme. (I'm not sure if WordPress 4.7's new custom css feature will affect the admin pages. I need to investigate this.) (Add instructions here.)
Suggestions and Problems
If you have a problem, or want to suggest a feature, please do so on the plugin's dedicated support forum over on wordpress.org.