That is so sad.
Growing up I had fights and such with my siblings (1 older sister, 2 older brothers, 1 younger brother, 2 younger sisters), but we all get along now.
I am lucky that they all live nearby except 2 (younger brother passed away, youngest sister lives in DC). We get together as a family (mother and siblings and their kids as well) and I see all of them at least once a month on top of that, if not more.
My youngest sister is the only one I don't get along great with, but we get along and talk when she does visit.
One of my brothers is my motorcycle ridding buddy, my oldest brother is wanting to get a bike so he can come with us. My oldest sister and her husband are coming up to the lake house with us this weekend.
While I don't see my cousins real often (3-4 times a year), we all get along well, my younger sister and her family have gone on several trips with one cousin and his family.
My kids know all their aunts and uncles and see them often, as well as their cousins.
As far as strange things they do, well, the brother I ride with has a horrible habit of not answering his phone or returning calls.
My youngest sister has some odd views of the world compared to the rest of the family (she has become very liberal, and her husband is as well. The rest of the family is pretty conservative).