Ok, basically you're saying that by listening to these bands I am immersing myself in sin and supporting their Christ punching ways. Well, here is my rebuttal
A) I am not sinning because I am focusing on the positive aspects of the music, and weeding out the bad. Sort of like reading the NT where Jesus murders 2,000 piggies by allowing devils to enter them. I mean, God, I know pork isnt your thing, but come on, don't you think you ended enough life in the OT?
B) I am not supporting the band. Sure, I'll let my friends know about awesome music, but I am not actually buying their stuff and promoting that crap put of it.
C) If it's sin, God will forgive you if you are genuine in your repentance. God doesn't want anyone to go to hell, and He makes that clear in Ezekiel 18:
So, if you've shaved, wear clothes with more than one fabric, or punch a baby, ask God for forgiveness and thou will be forgiven.