Are there not class actions against the RC church because of molestations etc., on the grounds of emotional harm done the victims?
Yes, but they are all for the same type of harm (sexual abuse), not various practices that people disagree with. Further, sexual abuse is obviously a tort with recognized damages remedies. Sexual abuse is not part of the theology of any established religion, unlike shunning. Even if you want to limit your hypothetical lawsuit to shunning victims, shunning is legal and sexual abuse is not. It's pretty simple.
the harm is not caused by doctrine
Of course the harm is caused by the doctrine. Strictly enforcing the policy (or coercion, as you call it) is all part of the doctrine, whether you agree with the doctrine or not. Personally I think the shunning policy is disgusting, but you even used the term "loved ones" in your response. Do you really think the government should be telling people who they have to love and be close with? I don't, although you are free to disagree.
thousands of people have already suffered harm from the WT's intentional interference in their familial love
You need more than just harm to have a case. If someone walks past you on the street and mockingly calls you ugly, you might suffer emotional harm, but you have no legal cause of action. If a man seduces a married woman and causes her to leave her family for him, the family certainly suffers harm, but there is no legal recourse against the seducer in almost every jurisdiction. And these are examples that don't even have the additional obstacle of freedom of religion to overcome.
Please , somebody tell me this isn't so!
It would be nice if it wasn't so, but not only is this the law, but here is an example of it actually happening within the past year:
Since you said you are interested in what Band on the Run thinks, she has posted in other threads not only only that shunning is protected conduct, but that she agrees with the right to associate with whoever you want. You can probably find such comments with a search. I know you have good intentions. Not trying to give you a hard time, gone for good. Just observing that the way to fight the WTS is not with shunning lawsuits. At least not in the foreseeable future.