Super judgemental people, of whatever stripe, should be tolerated. You would go along to get along with the extended family, unless they are actually terrible/evil/bad/vile/nasty etc. In my experience, extended families keep things light and fluffy when they have a reunion because each person and nuclear family have many different personalities, situations, and opinions. A positive event is maintained. If the majority want to discuss complex hot button topics, then I am sure in that scenario they would do so. Sounds like your extended family is normal to me.
You are frustrated over a large list. I really hope that angst aint weighing you down frequently, because it will poison your own happiness. Only you can walk your path. Only I can walk my path. Only "Uncle Bob" can walk his path. etc. The reality is that there will ALWAYS be sensitive and awkward topics between humans. Being angry at the 100s of millions of different ways people view reality does not seem very productive to me, especially if ones goal is to uncover truth. You finish off with quite a few angry sounding sentences. Tranquility is logical. But anger, at least in my life, has NOT resulted in good decisions. To me it is the lizard brain rising up and taking control.
I believe you are better off putting the vast majority of focus on improving yourself, next on being the best person you can be for your nuclear family, a bit of effort on improving your extended family, and a smidgeon on making the world a better place. (Making yourself and your family the top 2 priorities is actually the best way to improve your city, county, state, and country anyway).
Appreciate that you did not take my comments as a personal attack. Opine on the above paragraphs, if desired. Laterz.