I'm about 187lbs without gear and a Vet Intermediate. I'm currently running a 6.4kg/mm rear spring with 98mm of race sag and 165psi in the forks. The compression stack in my shock is slightly modified to add about 10% compression damping over stock. I plan on going a little stiffer in both the compression and rebound stacks on the shock. The forks are underdamped for me as well. I plan on increasing the compression and rebound damping so that i can run slightly lower pressure (160-163) for small bump compliance.
Gearing - I raced with the stock gearing (12/53) at Glen Helen and it was no problem. Was hitting 60+ mph down the start straight. That said, I just went down to a 52 tooth rear because i didn't feel like special ordering a 53T from Dirt Tricks, and it definitely smooths out the power. I'd say if you find yourself fighting for traction a lot in map 4, gear the bike down a bit. For serious motocross, i would not suggest going below a 4.0 final drive ratio. If you are on a tighter track, you'll miss that grunt the stock gearing gives you. I ran the 12/52 in supercross and wish i had stuck with the 53T in hindsight. So stick with 12/48-53 or 13/52-53 is my suggestion.