To redistribute a program that uses the Hag GUI, you will need to also include the "hag" base directory that contains any themes that you are using. You can freely remove the Theme Compiler or any unused themes.
The hag base directory can be renamed or moved, provided you call the function HagBaseDir in your program to point to this new directory.
If you are not redistributing Hag in source code form then the easiest way to comply with the license is to leave hag-license.txt in the hag base directory. Otherwise, just leave the license in the hag source code.
You can also contact me directly - I make an effort to reply to every e-mail.