No four-letter president had ever been re-elected (Polk, Taft, Bush) - Kerry
No father or son of father-son presidents had ever been elected (Adams and Adams, Bush of Bush and Bush) - Kerry
All '00 presidents were re-elected (Jefferson and Roosevelt) - Bush
We also used to hear about the ZERO factor, if you were elected in a year ending in zero, you did not survive your first term.
Ronald Reagan showed that "statistics" like these have no bearing on the outcome of future events. George W. Bush is the second president to survive it.
You're last one is wrong. It was McKinley who was re-elected in 1900 and then assassinated in 1901. How about no two consecutive presidents have served two full terms since it was accomplished by Jefferson-Madison-Monroe?