Question 1: How did Optimus Prime become so powerful?
Optimus Prime comes form a long lineage of Cybertron royalty called the Primes. Cybertron lived in peace with the Prime monarchy until someone decided “why should they get all the glory?” and then the Decepticons came along, and you now have what the modern world calls a “democracy”.

Question 2: Why is there no one driving Optimus Prime?
Optimus Prime, like all Transformers, is a living thing, capable of moving himself, much like how you can walk and run, so he doesn’t need a driver.

Question 3: Why is there someone driving Bumblebee?
That someone isn’t really driving Bumblebee; Bumblebee is really driving himself, just like Optimus Prime. when you see someone in Bumblebee’s driver’s seat, usually he’s just holding on to Bumblebee’s steering wheel for dear life. He doesn’t look scared because he also wants to look brave.

Question 4: How do the Autobots transform? What buttons do they press on themselves?
The same way you wake up every morning and go to sleep at night, or go pee pee or poo poo. There are no buttons to press; when you need to, it just happens.

Question 5: Do they run on batteries or electricity?
Transformers run on Energon (see http://transformers.wikia.com/wiki/Energon_cube). It’s like electricity, except it’s liquid and pink, like rose syrup with too much water.

Question 6: Why are there bad guys to fight?
For story tension. If there were no bad guys to fight, the Autobots would just be sitting around, drinking beer and answering trivia questions on mommy blogs.

Question 7: How did the Decepticons come about?
See Question 1 on democracy.

Question 8: Why must there be bad guys?
They make life interesting.

Question 9: Do the good guys fight among themselves?
All the time. Sometimes over what TV shows to watch, sometimes over the last piece of pizza, sometimes over a pretty red-haired female reporter in a yellow t-shir… oh, wrong cartoon.

Question 10: Why can’t we just have a movie only with the good Transformers?
Then it wouldn’t be fair for the bad Transformers. Must learn to share screentime, right?