Trevin Martin was followed because someone thought he was casing houses. There is zero evidence to support argument that he was followed for any other reason. That of across did not stop the media from convincing people it was the reason he was followed and they went so far as to try and create the evidence when they couldn't find. The only actual evidence of racism was Martin calling Zimmerman a cracker.

Why do we assume he wasn't casing houses? He had been caught at school with burglary tools. Media down played that while continuing to show a picture from middle school and taking about skittles. They did because they know people are sheep and will usually believe what they are told to believe as long as it feels true.

Of course Martin was not shot for casing houses our being black in the wrong neighborhood. Sorry that is a simple fact no matter who firmly people insist on believing it isn't. What we know is Martin made it home and then circled back and attacked Zimmerman. The eye witness said he was siting on Zimmerman's chest beating MMA style. The only injuries Martin had was a bullet wound and beat up knuckles. You can argue that Zimmerman still shouldn't have shot him but you can't make a reasonable argument that he was shot for being black in a white neighborhood. Do you honestly believe Zimmerman would not have shot a white man who was beating him senseless? IF you do I think that say more about your views on race than anything else.

As for your other factual errors, because virtually all of it wrong.
It was not middle class neighborhood
Zimmerman was not on top but on bottom being beaten. That is why he is the one with split scalp and broken nose and Martin the one with the beat up knuckles.
No matter how many times the media repeats the fallacy that Zimmerman was explicitly told not to follow him that never actually happened. Go back and read the transcript and show me where he was ordered not to and please no silliness trying to argue that saying it wasn't necessary for him to follow him amounts to an explicit order not to. The argument that it does if the best evidence I can show that people turned their brain off in order to believe what they wanted to believe.