L4: The Prudecutor actually does fairly well here, calling out the bullying of W4/SIL4 and wondering what W4 does to show an interest in LW4's activities of choice. But one goes beyond that to wonder how on earth LW4 got to this point in the first place. Surely people in D/S relationships who choose to carry it out of the bedroom ought to disclose the fact in the first place. LW4 perhaps needs to request such a contract, with one important exception written in. Otherwise, the obvious answer clearly is seven letters long and begins with the letter D.
L3: It may be one thing not to say anything to a pregnant woman doing something that might increase health risks to her potential future child. But to extend that to a regular vomiter is taking delicacy to a new extreme. Just don't follow the line of discourse the Prudecutor recommends. The "lovely young woman" with her "bright future ahead" reeks of Standard Issue Soft Soap. Be kind but firm, state the facts, offer what assistance with which you can follow through, and leave the ridiculous shibboleths out of the conversation. They come across as condescending, not the right note here.
L2: This is what LW2 gets for having gone along without initiating the Sexual Preferences Conversation well in advance of marrying. Her use of the term vanilla might indicate her familiarity with the writings of Mr Savage, yet she consults the Prudecutor probably through fear of being told to dump her husband. Somehow I don't see where her "kinkiness" comes into this. But her final five words practically constitute a dumpable offence. Divorce would be kinder to H2, who could start again with a suitable partner. But LW2 won't, so let her try to fudge her way into improving their marital relations.
L1: The Prudecutor omits to ask why LW1 has been trying to revive a relationship with F1 and SM1 when the whole thing is clearly just window dressing and empty show. F1 might perhaps be forgiven for his marriage to SM1, as aging men supposedly cope badly with living as singles. But the Prudecutor is right; SM1 goes beyond the pale. Things should not have reached this point. An attempted reconciliation is a drastic step in the wrong direction when LW1 ought to be urging F1 as strongly as she can to divorce his wife now, not bringing F1 for visits.
Moral: "A friend's work is never done." (Winona Ryder in Heathers, in the bathroom after lunch.)