The letters be HERE.
LW1: Craaaaazzzzzy. Or stuuuupid. Or booooooth. Guess what: these are your inlaws' cards, not yours. You can send any kind of card you want to your own family and friends (got any of those, you freak?). And how dare your inlaws be pleased that their children find partners of their own and bring them into the family circle. This sounds like a rather nice family circle. Why don't you stay out of it and make everyone happy? Alternatively, you could sit for the photo and pout. You sound good at that.
LW2: What she said, again. How in the world are you even contemplating staying with this man? Oh yeah. He's wonderful... but. You too, lady, are a freak.
LW3: Freak! Leave that poor dying man alone. Or not. My first reaction is that this is just too icky. But then I think, why shouldn't he get some while he can? My only worry is that she's too into the dying thing. If he weren't terminal, what would the answer be? Medical secretary/patient does not sound like a dealbreaker.
LW4: I'd rather have any gun-related discussions far from my home, and handled by someone else. Does the 2nd Amendment give everyone the right to terrorize their family members?