re: the "principles of natural justice" - I'm not a lawyer but what I gathered from reading a few articles about it is that it seems to apply more to the government dealing with non-legal administrative decisions than private memberships:
Failure to Observe Principles of Natural Justice
"This Court has affirmed that there is, as a general common law principle, a duty of procedural fairness lying on every public authority making an administrative decision which is not of a legislative nature and which affects the rights, privileges or interests of an individual "
The other challenge is that the internal rules, even when "defined" such as in the Shepherding book, tend to be rather vague (probably intentionally so). Therefore finding if they have followed them to the letter or not would seem to be difficult and, even if they didn't, it feels like it relies on the previous claim being of great legal consequence to make it a crime.
I can fully understand the desire to "strike back" at the WTS but I wonder if sometimes it does more harm than good. It's fighting an opponent on shaky ground when they have all the advantages of resources and the tag of "religion". Maybe your counsel has told you this and you want to go ahead anyway, maybe they are encouraging you and they shouldn't, maybe you have a great case (as I said, I'm not a lawyer) so I wish you well however it goes.
But just remember - we've often lost a lot because of the WTS and dedicating our time and energy to retaliating against them, while oh so satisfying if we can, isn't always really best for us and for our family.