AAQ, I agree that like-mindedness is more important than nusach, money, or ivy status. It’s often the families that accentuate the differences and amplify the friction. My children married into different “statuses” and I respect them all.
As for the advice I wish I’d gotten, I got it instead from a short story I read in Hebrew Language class called “Same’ach B’chelko”, to be satisfied with what I have. So as far as material things go, I’ve always been content!