1) It has been speculated that planets can [also] be destroyed by colliding with planetoid objects.
2) If you have ever seen the movie The Black Hole then you should know that the earth getting sucked into one is by no means a foolproof way of destroying it. It could possibly be sucked in and maintain all of its properties.
3) A supernova will happen eventually, and will consume the earth as it expands.
4) The universe may expand to point where it may not be able to expand any more. Therefore, it may start shrinking. Even if this does happen it will take many millenia for the universe to shrink down to nothingness.