Didn't know half of these! I do think Dashboard Confessional is a stretch for the given descriptor, but that could easily be sour grapes for it being so difficult. Tough grid.

Definitely easier after doing the other. Clever crossovers!

Some obscure bands here I grant you but not important in this case I thought, as you didn't need to know anything about the bands, it was a wordplay spot the theme puzzle rather than a quiz. One definition of dash is "to strike or knock violently" so I think it does fit that group. Thanks for your feedback :)

Fiendish indeed ! 'Violent actions' covers two groups & nine bands ?

I’m too old to know these bands