I'm an A/C, neither AA nor CC. Not a lot out there on that, some say "slow" is dominant, but that leaves me confused because I have none of the problems you've described and I drink 200-400mg of caffeine a day (monster energy + 3x 12oz soda).
A/C is still considered a slow metabolizer. This is just one allele that affects caffeine metabolism... there is still probably a ton of variability from person to person within the same allele here. I am A/C and have all of the problems described here.