I remember that Futurama episode, that was funny! He actually ended up becoming his own grandfather!
As for what Daphnes said about trying to change the future causes the future to happen, I'd like to quote the movie Next: "Every time you look at the future it changes,
because you looked at it." If you saw the future, no matter what you saw, your future would be influenced by what you saw. In some stories, the future you saw only happens because you tried to change it, where as others show the person changing what happened because they saw what could happen.
Honestly, I didn't realise there were this many time travel incidents in the series until I started this thread!
I would also have liked to see the Ellimist talk about the Time Matrix, as do most fans I imagine. I would why he even made it. Maybe because he knew it would be needed to set the events in motion that would create the events of the series?