Based on Slipknot alone, I would do any quilting in red - maybe zig zags, something sharp and jagged. I think the studs would be a PERFECT embellishment. And I like the black crackle as opposed to plain black sashing with black blocks. Breaks it up a bit, but keeps with the theme of the band.
And I know exactly what you mean about the never ending ideas. I've had about 10million plans for the quilt I'm working on for my husband. LOL