The key bindings for tkoutline are current (21-Jan-03) a bit haphazard. The page at http://wiki.osafoundation.org/bin/view/Main/BasicEccoOutlining has rather detailed description of how the Ecco Pro outliner is setup.
Here is a reference detailing what the old Macintosh More outliner keys do http://www2.rhbnc.ac.uk/Classics/NJL/more3ref.html.