Being pretty disgusted, I shall be pretty brief.
L1 - One could go through the motions of cross-examining LW1 about her flexibility - but we all know the answer is Not Very. And that's fine. One might cross-examine the BF about what avenues to Paradise he might have proficiency in constructiong, but he's probably been through enough. Given such an otherwise wonderful object, some people would try every position in the almanac twice a day and thrice on Sunday to make sure they're Just Not a Match. Others might look into triangles or parallelograms, but LW1 gives off too much Marcia Brady to be sufficiently game for the sort of hard work required, and that's fine.
Moral: One might be well advised to remember that Something Suddenly Came Up bites in more than one direction.
L2 - This is really a technical question, and I loathe technical questions. LW2 sounds like the sort of pushover that people who could really use such a friend so rarely know in real life. That guilted out because a friend of an acquaintance made the rather bizarre request for a donation of hair? The friend has clearly learned from the master - Danny Bonaduce. This has the DB touch all over it. It would not surprise me a bit if the friend has been madly jealous of LW2's hair for some time now and has seen an ingenious way to get rid of it. But LW2 has a grand opportunity to improve her friend's knowledge of literature with a reference to a well-known story about another donation of hair, and if worst comes to worst and she feels truly compelled to lie she can claim that her husband thinks he will be surprising her with a present of expensive combs.
Moral: If LW2 wouldn't (and it seems reasonable to assume so from the letter) cut off her hair to buy her husband a watch fob, she can hardly be expected to cut it off to make a wig for the child of an acquaintance when asked secondhand.
L3 - Now the potential for effective cross-examination here is off the charts. One might inquire into exactly what sort of questions LW3 had to refrain from asking in order to secure her radiantly happy marriage (and there were, one might reasonably presume, a good many of them), but the thought of being landed with another brief in a divorce case before Mrs Justice Appleby is too offputting. But one might put a few pertinent questions to the husband and the bride while LW3 happens not to be in the court. There might have been a few little games going on with LW3 that might be useful to know without LW3 being on to it.
LW3 really has a very strong air of Jan Brady about her. Noone wears the mix of righteously and overreachingly offended air in quite the same way. And the bride has broken the Girl Code. Not realizing without a word ever passing her friend's lips that the marriage was based on a veneer only of mock forgiveness extending only to the the husband, and that the vile woman who had to be blamed for 250% of the trouble between the couple was to be Shunned in Perpetuity. The bride has committed a serious offense, very serious indeed. LW3 would be quite justified if she were to seduce the groom, for instance. Or perhaps it might be more effective to create a grand scene at the wedding, rather akin to the time that Jan wore a black wig to a party.
Moral: It seems almost unfairly to LW3's benefit that Eve Plumb came out of the Brady Bunch with the most chic reputation of all, doesn't it?
L4 - So you wanted to be Susan Dey and now you realize you're not up for it? Join the queue.
Moral: (and this one's for serious Bonus Points) Honey Lingers.