http://www.dreamwedding.com/article/guest-list-drama-5-people-you-dont-have-invite
1 and 2: Unless you are very good friends with your ex, why would you?
3: Eh, I guess this depends on how you feel. I wouldn't, but FH wants to.
4: wat
5: I wasn't going to comment because the list was just "meh"-worthy, but this made me do it. I personally find it so rude to not invite SOs.