I personally think the heart problem is strictly with shape... Purely a suggestion, as the piece does look amazing...
Maybe a slightly shorter wider heart, with more "voluptuous" curves?
To explain it another way, starting at the crevice at the top, start slightly deeper, come out in a graceful curve, and around the sides, but once you get to the "vertical" part of the heart (Math head here, vertical tangent line) come in a little harder, making for a tighter radius when you curve back out to the tip... If that makes any sense whatsoever... Ill try to find a picture...
EDIT:
A picture I did a while ago, but see how the left side is shaped? That kind of inspiration would make it fit the rock n roll idea a little better to me.
I also wouldn't rule out slight asymetry... Just my .02, that picture is amazing regardless, and far out of my legue using a computer. Fantastic job man!