Mahler,
Thanks as always for your Monday posts. I always look forward to reading them, and they put me in the right frame of mind for the rest of the week.
That being said, urban legends are a bit of a hobby of mine, and at least 2 of the 5 stories in your post fit the bill.
#2 - Mrs. Nat King Cole
http://www.snopes.com/luck/trump.htm
#5 - Blood Transfusion
http://www.snopes.com/glurge/transfus.htm
I still think the lessons are valuable and worth remembering, but I just thought you should know.