I really dont know how much elevation will affect your car, however I've ran a 14.6 @ 91 I believe on a bone stock 2.0 04 wrx.
I'm Stage II'd now, so hopefully I can nail a 13 this time around. btw, that 14.6 was with a 2.0 60' time.
I really would think you should be faster, but the launch is EVERYTHING, if your afraid to abuse your car, the dragstrip is not the place for you.
I'm not really into abusing my car that much either, so I won't try to shave every 10th of a sec off my time with repeated runs, I just drag to see my traps and to have a little fun.
So get out there, give your car a good dump at around 5000 and hold on tight.