should george zimmerman be forced to give up the money he made from auctioning off his murder weapon or is america the worst?

If with all that's going on here THIS is the thing that to you makes us "the worst" you've got some curious standards. 

That wasn't a "murder weapon." He was adjudicated not guilty by reason of self defense because it was proven that "little" Trayvon was on top of him fighting him when GZ shot him. So, no, he should not be forced to do anything. 

His 'self-defense' weapon is his to sell as he pleases. Hopefully he will use the money to buy more weapons and train other law-abiding people to defend themselves too, until drug fueled racist ghetto thugs are finally pacified enough not to even try being violent anymore. That is what guns are REALLY for, not to actually kill people. 

Peace is only maintained through skill and strength, not placation and cowardice. 

Jesus taught us that two armed men among every twelve is a sufficient proportion to keep this kind of peace when Christians are living under 'secular' rule, (Luke 22:35-38). This became the basis for the holy knighthood and later the American right to bear arms.

Christ also gave us a separate set of parallel instructions for when we are 'in charge' and our system makes deadly arms unnecessary, (Luke 9:1-6).

Zimmerman was found not guilty. Zimmerman was attacked by Martin, was beaten, and fired in self defense.