Hello zwergo,
welcome on SEBLOD forum.
For the point 1, you must put an "End" Tab to close properly all tabs. To make Tab, you must have:
- Start Tab -> with Label
- Panel -> with Label
- Panel -> with Label
- ....
- End
The group-identifier is a name which will be added to all tab. If you don't have multi tab on the same page, effectively you wont see any thing,
For the form validation with tab, if you have make tab like describe above, and validation don't work anymore, please can you post in the tracker.
Best regards.
Lionel