Thanks for your help, Aaron. That got me closer to the solution. Adding
to the kernel parameters allowed X to start, although the system froze once I entered my password. So after understanding this is a memory-related problem, I tried to backtrack and think of any other memory configurations I've made. Then I remembered experimenting with setting my RAM to 128-bit ganged mode after an ASUS technician advised me the results would be "unreal." I set it back to 64-bit unganged mode and everything is working perfectly now. I think I'm just going to keep it real from now on.