Your GSR has a knock sensor, but unfortunately I've heard knock can be a bit unpredictable while in VTEC... some cars are noisy, others not. Really you need to datalog for your vehicle and establish a baseline, and then watch for anything out of the ordinary.
As for the nitrous tuning, might actually drop a post in the Integra forum... quite a few nitrous users there. I'd keep it straight up on the cam gears unless a dyno tells you otherwise.