westboro baptist church & elliot rodgers.

on the subject of "nature vs nuture"

It is interesting.  I often hear about how Westboro and Elliot Rodgers are mentally ill, but is that a fact of nature of nuture? 
The nature argument appears to give the individual control over their own actions, and ultimately it is a free will argument.  Nuture puts the responsibility of a person's actions on the hands of fate.  Therefore nuture puts forth a deterministic argument of the world.  A friend said Elliot Rodgers could've done it because he had a chemical imbalance.  Chemical imbalances are not within his control, but he could've been born with these chemical imbalances, and they could've been corrected with drugs.  Are these chemical imbalances innate?

Also, politically speaking, do we really have first amendment rights to free speech?  Both Westboro and Elliot represent vastly unpopular hate speech and both have been written off as insane.  If prevention was possible and Elliot Rodgers was detained, wouldn't that also detain his speech because the mental facility will probably limit his right to probably publishing options?  Wouldn't locking Westboro up be limiting their speech?  We hate them, but this insanity case feels like a loophole which if found could be used against "the nail that sticks out--that one leader who could have radical views that could change this country for the better silenced as insane before anyone could hear."

I end with:
What is the difference between a person who is insane and one who believes in extremely unpopular views and expresses them? 

From a psychologist I asked, the difference between the ill and not-ill psychologically speaking, is the amount of stress they feel.  I'm still confused because 99% protestors feel lots of stress about police, politicians, and lack of jobs while a mental person may not even understand what is going on.