I think you’re the most correct person here.
OP, it’s your life and relationships. Of course people on the internet will tell you to pull the trigger on the nuclear option, because they don’t experience any of the fallout of you making a hardline decision.
I’m not saying go to the wedding. I’m just saying consider how it might affect your relationship with him and the rest of your immediate family and decide if that’s going to be a better situation overall, before acting.
I think 40 - 60 makes more sense. 30 would be the age that someone would be too early in their career to rule a country. If that person has risen to a position that they would be considered for president by 30, the chance of them getting to that position without significant nepotism is too low.