I haven't figured out exactly how the pages listed under "Hide Pages" are organized, but however it is, it is extremely difficult to use.
If you hide a page which is a parent of a tree, the rest of the child pages populate the menu automatically.
I would suggest incorporating this part of your plug-in with the "PAGES" display, already a part of WordPress. Put your check boxes in a column much like your word count.
In order for this to be a solid plug-in, you have got to address the issue with the parent/child menu items, and how they populate in the menu.