1. Eat that humble pie, confess that you don't know as much as you thought, get past it. To maintain your dignity, focus on the work, not the politics.
2. Unfortunately quite common.
3. No. Try not to dwell on it. Pity them quietly, stay focused on the work, don't lose yourself in their negativity. Treat others as you'd have them treat you (even though they don't yet), and lead by example.
If any consolation, you're going through what I call "celebrity training." Since moving to LA, I've noticed particularly successful/famous people can be particularly difficult, demanding, and even insulting.
When you meet their assistants and see them graciously cope with their superiors being completely insulting, demeaning, abusive, awful human beings, it suddenly becomes clear: That is why you want to get to know the assistants.
It's like they know how to speak a foreign language reserved for a special few- some of the most powerful, intelligent, successful people in the world. They all speak verbal abuse.
Most people when they hear verbal abuse freeze in shock, do as instructed, feel embarrassed, explode in retaliation, or run. But if you're fluent in verbal abuse, you learn how to ignore it, see past it, even reform it, but most importantly, they learn how to work around it.
Also, keep in mind that a lot of your fellow bad-asses may have mild autism/aspbergers, which makes it hard for them to tell when they're offending you. If you get up in their face about their shitty behaviour, you might be surprised by their surprise. They may not even be able to detect how much they're upsetting you.
If you haven't already given them feedback, then you should. A simple "Hey, it kinda stresses me out. Maybe less of that?" will do. Remember to do it immediately after an infraction. People are like dogs, and the sooner you interrupt and correct and throw it away, the more likely it'll stick. Also like dogs, people need gentle reminders, as they'll keep slipping up for a while until it sticks.
Keep it light and funny, not dramatic. Try a quick, soft-spoken "rawr?" with about the delivery and tone you'd use to say "lip?" while pointing out they have a suggestive dollop of sour cream on their upper lip at a house party, and you just want to bring attention to it very subtly for their benefit.
Also remember that an important part of training your dogs is to reward, not just punish. While looking for infractions, you also want to look for spontaneous moments of good behaviour and thank them for it immediately, even with only a smile and a nod.
Best of luck!