LW#1: You say your gf of six months has made out with three of the groomsmen in her friend's wedding. That begs the question, how many groomsmen are there? Is this a high or low percentage.
Sounds like your gf is a drama queen. "I'm just trying to prepare you" in this case is "I just want to see how wound up you'll get over this." Apparently it is working well according to plan. Since apparently it has you twisted in knots, she has you where she wants you. Evade her trap not by checking out of the wedding, but by checking out of these games all together.
LW#2: "Squandered millions." I'm imagining having millions to squander. I'm imagining squandering more than $50.
Look, you have the right to say, "No way, you guys are toxic freaks and you're going to have to make do for yourself." Which is kind of mean. Or you could say the pere needs to put his assets in some sort of trust that your husband disburses regular payments to him from before allowing him to move in.
Basically, you have some serious crap here. But don't allow people to bring their crazy into your home: Set limits and boundaries before the first Samsonite appears on your doorstep.
LW#3: How old is your husband? God, they are both idiots. Frank didn't need to punch anyone. Did he expect anyone to know he's allergic to mustard? But mostly you are right, your husband is an immature moron.
I think, as far as your marriage goes, if you're still angry (and lordy do I get that), that's one thing. But if you're harping on him and being blamey, you're not helping yourself.
I kind of get the feeling that you've been thinking your husband is an asshole for a long time and that this prank has disrupted his livelihood, put you at risk (and could have killed Frank), and caused potential litigation has shone a new, vile light on someone you already thought was a nitwit. You are feeling contempt, a marriage-killer. He is feeling defensive, which is not conducive to growth. And to be honest, he needs to take a hard look at himself and change his ways. If he doesn't feel bad, stupid or mean for what he did, that's not good.
What does this mean for your marriage? It's a bad omen. Can an immature man and an angry woman make it? It would take a lot of work on both their parts. Are you up for that or just fed up? That's your call.
LW#4: Document, document, document. Talk with your advisers.
I'm as shocked as you -- who treats fourth graders like this? How mean! -- but the fact is you need to come clean about her behavior to, at the very least, the people in charge of your program.
It sounds kind of Mike McQuary-ish, I know, but are you even expecting her to write you a positive evaluation at all? She seems like she'd be happy to throw you under a bus, considering how much larger the stakes are for you than for the fourth graders.