To be honest, there's really nothing wrong with your current bike. It's not holding you back at all.
I think you might be better served spending your money on training books or coaching to help you maximize your training and efficiency.
As for carbon vs. aluminum for crits, that's kind of an outdated mindset. Aluminum was encouraged because aluminum frames are cheaper to buy and replace than carbon should you crash. And while that is still true, carbon repair is now a lot more common, and carbon can be repaired for a lot less than a new aluminum frame.