Debate and discussion are good- I don't think the thread needs to be edited. Also, your cousin's ex doing this is no different from a direct family member- you knew her, so the connection is there. Learn from it, especially if you remember anything she said or did that had anything to do with her situation.
Re: your growth being stunted by losing your GGM and father without getting a chance to say goodbye- that will stunt your emotional growth if you let it. That's far from the worst thing that could have happened to you, to be honest. If my parents were here to read what you posted, they'd tell you to stop whining because they had it a helluva lot worse when they were young. My maternal grandmother dies when my mom was 9 and once she was gone, my grandfather didn't want the kids who were still at home. My uncle was put on a train to California with $5 pinned to his sweater, so he could live with some relatives. He was 3 years old. If you want to complain about not being able to say goodbye, go ahead.
I don't know how old you are or when they passed, but if you knew your grandparents and any Great grand parents, consider yourself damn lucky, especially if they were able to communicate any good information to you. If you spent any time with them at all, you need to know that many, including me, can't say that. I never knew my dad's parents and although I saw my grandmother in the nursing home a couple of times, she wouldn't have known who I was anyway because of the strokes. That grandfather died before I was born, as did my maternal grandmother. My maternal grandfather lived in Kansas and I only saw him a few times, so it's not like we had any kind of family relationship. I really wish I had known my grandparents and have always felt that I missed out, realizing that not all parents and grandparents are particularly worth knowing. We did have some neighbors who were like substitute grandparents for a lot of kids in the neighborhood, though. They were good people and it was definitely good to have them around when I was a kid.
Rather than complain about a few bad things, look at the good things and be happy you had them.