Further to that
1. Yes it relates to the project object.
It is part of the project default layout page and also of some other layouts.
Those layouts are created with tools not available to the user.
Collaboration is one of the tabs in the project layout.
The only things available to the user are the make the tab inactive and select actions for the tab (by default there are none to select from)
That is as far as you get.
The tab ID suggests that in the database it is in document management part of the application.
However, as Dave points out that area is not accessible in studio or any other means.
2. You cannot do that in a supported manner
3. Because your cannot see those fields in the GUI in the process administration for the project object you cannot do that in supported manner.
4. Collaboration manager and participants are not within the rights administration, but they do consume licenses as long as assignedwhich you should take into consideration when you try to release licenses by removing rights and inactivating users.