How to selectively invite family members....

It is never easy. Family politics get in the way.

I think the hardest situations is where there is mistreatment or abuse which is not recognized by others. If it is a sibling or cousin, parents can still push to have that person invited. Maybe just say we just did not get along and I don't want old conflicts interfering with my wedding day. Divorces often create problems but it generally is best to assume that divorced people will still behave okay in the wedding event.

I didn't have anyone ask "why wasn't I invited".

I think people "get it"... you can't invite everyone.

You shouldn't need to explain to anyone why you aren't inviting them. If they ask you directly whether they are being invited, you could respond with something along the lines of, "Unfortunately, due to limited venue capacity, we weren't able to include everyone that we wanted to." You don't need to explain how you decided who to invite and who to leave out, etc.

I think its always best to be honest about it. I have an aunt and uncle who are not very POC friendly and are super religious. My fiancé is an African American woman, and I have cut ties with them a while back and shared that with anyone in our family that asked. Usually not inviting a person to something is a very clear cut and dry thing, if you feel you need to explain it and still want them in your life reach out. If you don't want them in your life at all just explain that to the people who ask, they should respect your decision hopefully.

You don’t need to explain your guest list to people. If they ask, say “unfortunately we couldn’t invite everyone, but look forward to catching up another time!” Having said that, it’s least dramatic to invite in “circles” of closeness to you, ie all cousins or no cousins etc.