We could fly it into the sun, the problem is that until we have a space elevator the only way we have of getting it out of the atmosphere is via rockets and a rocket explosion with a nuclear waste payload would be very bad.

Potentially, but it is much, much safer to dispose of it here.

What's even better is to recycle it, because 95% of the original energy is still in the "waste". And when you do use all of it, the remainder remains radioactive for a much shorter period of time.

We can just bury it in a cement casket.

There isn't that much of it once it is solidified and it isn't that dangerous.