And it comes down to this... Luke is actually the one that brings balance to the force, not Anakin.
When stated that Anakin is the 'possibly' the one its cause of the powerful potential he has...
But who says the most powerful should be the one.
Also If you have ever read 'Heir to the Empire' which is considered canon material and post ROTJ...
Luke actually learns a great deal about the dark side and its powers, and uses them without penaty to
his soul, thus in his path has attained a balance in the force. Even when Luke brings back the Jedi academy
the new rules are not as rigid as they originally were to be a Jedi, cause NO one can be perfect. And not to get
into a relegious debate but even Jesus wasn't perfect, he had his own flaws.
No one can be 100% good or 100% evil, there is always a shade of grey. Although I do think the original ideals of the
Jedi was to atain that 100% goal, but under Luke's new academy its more to find that balance in your life, and its a
constant battle within oneself ie: conflict, which is what defines whom you are and the choices your make.
So in retospect Luke was indeed taping what Jedi would call the dark side and using a force choke. Also I believe its all the same Force... its just how its used and the state of mind and motive behind the use of said power.