Custom node add/edit form - How to leave value of undisplayed field as set?
After some research I found out, that it is very important to have the full node form be added to the panel to get all fields (like publishing option, date created...), so the submit routine gets data for all node fields.

You can show/hide fields for certain roles using the Field Level Permission Module for the standard Drupal roles. But I like to use the OG roles to define the permissions. There is already an OG function for this under admin/config/group/permissions.

I did it this way:


Activate the node/%/edit page under pages
Create a variant for editing node of a certain type
Add all required fields, which should be shown to the normal user to the form and layout it
Add the submit buttons to the form
Add General Form to the panel, so that all fields, which are not build before are added to the form (like publishing status, author, date created...)
Goto admin/config/group/permissions and set the edit rights for the fields, the normal user should not see. The fields then are not on the node form anymore, but the values remain in the database.


I hope that helps someone else.