Agree with everything said. Flags and penalties would be great. And if they don't fix the AI, the "flip the bird" button would be a must. Great idea!
Only slightly off-topic: One thing I would like to see is the ability to control your own starts, especially with standing starts. This would be an option, so the hard-core people could control when they start, while newbies could still rely on the game to tell them when to go.
Back on topic: Of course, if you jumped the start, you would get a black flag and a stop-and-go penalty.