At a glance, the crash looks like it was caused by something in the audio engine. Which is weird.
Also, you say that OptiFine isn't compatible with newer Forge versions. I've tried 1.7.10_HD_U_B5, HD_U_B7, and HD_B7 all on Forge 1407, and only had an issue with HD_U_B7 in one pack (which went away when I switched to HD_B7).