Greetings!
There are a couple of things going on with your post. First, payment to the attorney has no bearing on the attorney-client relationship. Indeed many lawyers do pro bono publico work for free.
Secondly, communications that take place within the attorney-client relationship are privileged with very limited exceptions. The privilege is owned by the client (in this case the WTBTS) not the attorney. This applies to all communications, even admissions of criminal guilt or illegal activity, without such Candor between the Attorney and client, an attorney may not be able to effectively represent the client. The only provisos that work against this fundamental principle are that 1) an attorney owes a Duty of Candor to the Court and is ethically barred from misleading the court so he can't place a witness on the stand that he knows is being untruthful (suborning perjury) (though if the client insists the person may testify in a "narrative") and 2) an Attorney may not help to facilitate a crime, using the Attorney-Client privilege or relationship as a cover. (thus why some attorneys have gotten in trouble by being the messenger for mobsters and terrorists).
Thirdly, your whole post begs the question and makes an assumption that there IS illegal activity going on which is either not the case or ever been demonstrated.
having said all of that I can't imagine the stress and moral quandry of being a Watchtower lawyer. After all, there are many times that an attorney has to go against the client or take a position against the client's wishes out of what he is ethically and legally bound to do. Imagine then if your client is the equivalent of God to you. Very prickly position to be in indeed.
As an aside, The most difficult thing for a corporate attorney is keeping the line clear about who the client is: The client is the corporation not the individual members of the corporation.
As for any type of actions against the attorneys, the answer is no. Attorneys are generally immune for their exercise of the legal process and for doing their jobs which includes advising their clients to the best of their ability. Additionally, the standards for malpractice are unbelievably low so to win a malpractice claim (from a person with standing to bring such a claim of course) would be near impossible.
-Eduardo