Some of those are just plain creepy. Especially the kid that said he had smothered someone a long time ago. I would have freaked out if a kid said that to me and I would definitely be sleeping with one eye open.
I also have heard about the connection of birth marks and the cause of death in past lives. I haven't been able to find a lot of evidence supporting it though. It is strange that there were two different references to that. The one that talks about the kid whose grandfather had died of a heart attack just before the birth, and the boy was born or reborn with a birthmark on his heart. Definitely makes you wonder about the connection birthmarks have.