George Zimmerman Trial: Why is it important?

OK, so I know this particular trial has been getting a lot of hype and such, and I'm not really one that likes to follow trials and what not, but I believe that this trial is important to the country as a whole. Why? Because the trial of George Zimmerman has already been decided by the public (or how it feels) before it even went on trial.

 Many have an opinion on his guilt or innocent (with the press painting Trayvon Martin as a saint, and Zimmerman as a bigoted, racist, evil from the pits of hell, basically). NBC was even guilty of tweaking the 911 phone call to try and paint him as a racist guy (click here).  Sure, NBC says it was an editing "error" but come on... You expect me to believe that editing out the dispatcher asking what he looked like so it sounded like Zimmerman saying, "He's scary.  He looks black".  Come on.

When it comes to Zimmerman, I've had mixed feelings.  Why did he try to chase Trayvon Martin down?  Zimmerman did look pretty bloodied up, though, so I don't necessarily buy that he was actively hunting him down to kill him.  Was he really doing it in self-defense?  I don't really know, and neither did the press.  In fact, the only ones that decide are the members of the jury after hearing the testimony and evidence of both sides.

However, this hasn't stopped it from becoming politicized.  Obama made the comment back in March 2012 that if he had a son, "... he would look like Trayvon Martin".  (click here).  Why in the world would he make such a comment a whole year and 4 months before the trial even began?  If you ask him or his administration about the IRS scandal(s) (like the targeting of "tea party", "patriot", etc.; the outrageous wasteful spending; the leaking of SSN numbers; need I go on), or the Fast and Furious scandal, or Benghazi; he and his Administration have the same answer, "I can't comment on an ongoing investigation."  So, why did he comment?

As the head of the Executive Branch, shouldn't he be more concerned about law enforcement rather than passing judgement on what the thinks happened that night?

Again, I have withheld judgment on the Zimmerman trial, until I saw this video.  This video is an exchange between the judge and Zimmerman.

Here's my question: Is that legal?  Is the judge able to step in like this in a trial?  I thought the lawyer is the legal representation for the defendant, and that the judge should be addressing the lawyer, not the witness... I don't know if he's innocent or guilty, but he does deserve a fair trial.  That's a common civil right listed in the Bill of Rights (the 6th amendment to be exact... "and to have the assistance of counsel for his defence [sic]").

So, what are your thoughts?  Did the judge have the right to try and get out of him whether he would testify or not?  Or does that seem to be not the role of the judge.  In my opinion, it does open the door for appeal on either side to say that it was a mistrial.