I think Bumblebee's behavior mainly came from his wounded ego. All throughout the first trilogy, everyone loved him. Now humanity has turned against him, and he was made leader of the Autobots, bringing criticism from even his fellow 'Bots. I find it interesting that, despite his anger, and humans hating him, he still changes his appearance to please a human. I feel it shows a need to be accepted. Bee in AOE really helps me accept Bee acting like Sam's dog in the first trilogy. He's not acting that way because he's impossibly nice, but because of a shallow, desperate need for approval. I feel it makes him into more of a real person.
No problem. I'm just happy the vid has become as popular as it is. The song and character made it a no-brainer vid to make.