The officer was legally justified in pulling the kid over. It is a violation of MI law to use brights within 500 feet of oncoming traffic -
http://www.legislature.mi.gov/(S(hu...eg.aspx?page=getObject&objectName=mcl-257-700 - so blinking the brights was a basis for pulling the kid over.
The kid then violated the law by refusing to show the officer his license. While an officer can't force you to produce ID if you are just walking down the street, he can if you are driving - that is one of the conditions of having a driving privilege. By refusing to provide it, the kid was obstructing justice and gave probable cause to arrest.
Because the kid did not cooperate when told to get out of the car, the officer was justified in using reasonable force to pull him out. Once he was pulled out, he continued to refuse to cooperate with verbal commands to put his hands behind his back. The use of the taser was consistent with the use of force continuum police are trained on, because the kid was not cooperating. As for the use of a gun, we don't have enough information to tell whether it was warranted, but the injuries to the officer suggest it may well have been.
I know you like playing armchair lawyer, but God help you if you train your children that it's acceptable to act this way toward the police. As far as I'm concerned this kid's parents are at least as culpable in his death as this police officer. It's one thing to know your rights (my mom, then a judge, taught me not to answer questions asked about anything I had done when I was about 12), but that doesn't mean being a condescending, obnoxious wiseass who refuses to comply with direct, lawful orders from a police officer. As far as I am concerned, when I am dealing with the police in a traffic-stop situation, my entire job is to make them feel comfortable and sympathetic toward me.