“oppostate”: “You have to first send a letter saying you're leaving that specific congregation, and that you don't want them to keep records of you. . . . Basically if you withdraw from a congregation, you can hold them legally responsible if they retaliate against you for doing so. This makes for a situation where they cannot DF you for leaving the congregation.”
The only potential problem I’m thinking of, in practice, is that even though the congregation may theoretically have some legal liability for disfellowshipping a person in a manner which is unjustified and unwarranted (at least according to “natural law” or general “contract law”), they may just decide to go ahead and do that anyway, sending their little committee report to the Watchtower branch headquarters – because if anyone goes sending letters to the BOE in an attempt to tell them how to run things in his or her particular case, especially by putting forth some form of an ultimatum, the BOE is apt to consider such actions as a form of what they term “insubordination,” which probably would usually apply to an elder but may possibly be used against a ministerial servant or even just a rank-and-file member. (It all depends on how they may interpret and apply it.)
I’ve heard that the Watchtower has used “insubordination” as a grounds for committee cases and has even led to disfellowshipping of brothers. (And look what happened to our dear brother Raymond Franz when they even just suspected that he was rocking the boat!) Apparently “insubordination” is theoretically something they can use as a blanket charge against any who don’t tow the party line and who dare to not do what they’re told. (It seems that BOE’s tend to not exactly care for being told what to do by any “dissenters.”)