Currently it is possible to navigate using arrow-keys. Good.

-[F2] enables rename. ok

-But after rename, and confirming with [enter], the focus is lost

-Further navigation with arrow keys is not practical

Suggestion: Renamed element should keep focus

-I rename is enabled, it is not possible to abort.

Suggestion: Use [ESC]-button to abort ongoing rename.

Suggestion: Enable [ESC]-button as a general way for aborting and escaping and closing dialogs. (This is implemented in "Tag Editor", but fex not for "Tag Group Editor" and many other places)