There is a workaround for the issue of not being able to name/rename groups. Here is what I do:
1. right-click the Start8 menu and select Configure Start8...
2. in the Configuration dialog click Control
3. change Start button shows Start8 menu to Start button shows the Windows 8 menu
4. click the Start button to open the Windows 8 Start Menu
5. name/rename groups
6. change Start button shows the Windows 8 menu back to Start button shows Start8 menu
7. close the Configuration dialog