What should be disposed in your Flex Codes? (possible flex memory leaks)

According to the well-written article here, there are several possible scenarios which would lead to memory leaks.

1) You started a timer but forgot to destroy it (remove)
2) You created an event listener, but forgot to destroy it (remove)
3) You created loader objects, but forgot to destroy it (remove)
4) You created variables (references), but forgot to destroy it (null, empty array)
5) You created an annoymous handler, and you cannot destroy it ( #sigh )