Point Seven is really a rehash of Point Two.
Too many villains are based on characters who just want power for the sake of power. They need to have some motivation or redeeming trait that gives them a reason for their villainy.
How many times have you watched or read a story and found at the end a feeling of disbelief? The disbelief comes from knowing that the antagonist didn't have the three dimensional quality to hold the audience.
Discerning readers will return to a great story and a villain they can feel might have some justification for their actions, will help bring them back, or keep them hooked to the last page.
Strong motivation... that's the key to keeping your villain GOOD whether in Fantasy or any other genre.