Really tough to give insight because if you have a crack in the header the car may be a bit faster than it appears. 16.5psi is a little low but increasing that is really just going to make more peak torque and midrange. The stock turbo cannot sustain anything above that at high rpm (mine was around 15.5psi at 7k) because it is simply too small so it won't help with the quartermile. More boost is not the answer for a quicker time or faster trap speed.
Ignore reaction time. It plays NO ROLL in the end result of your quartermile time. Your first time out you should be as calm and relaxed as possible, concentrate on the launch and leave at your own time. May not want to sleep at the tree for a couple of minutes but a few seconds is fine.
2.2 60ft is slow for an AWD vehicle. Do some research on how to properly launch or send me a PM and I can review with you my technique on the stock turbo that always worked well and consistant for me.
Your 330ft isn't terrible considering the 60ft but you want to get that as close to 5.0 as possible. That will come as you get better at the 1st-2nd shift and as your vehicle makes the proper power.
Also, drag racing is pretty abusive, I personally wouldn't take my car out there and beat the hell out of it unless it is running flawlessly.