performance upgrades. (seeking advice)

[Jourdan]

2006 WRXtr... ok, listen. im just tossing this out into the wind. POSSIBLE mods in the future.
tell me no. or extra things i would need to do to make these things possible.
-i have a 10lb. tank sitting in my room, its a full nitrous kit. i figured maybe toss it in the car and spray no more than a 30 shot. is this a bad idea ? . can the wrx not handle it??? i know if i were ever to do these mods. i would DEFINITELY GET MY CAR TUNED.
-a full catback exhaust system is a good possibilty. + d.p....reccomendations?
-that cobb accessport thing sounds like a good idea.
-upgrade my injectors? to accomadate for the small shot if it was done?(maybe walbro255 fuel pump too if needed? i dont think for that small of a shot i would need it. but then again i could be wrong.)
- and of course a b.o.v. ......in the future properly tuned. reccomendations?

again, im just tossing this out there. i want to know if my thoughts are idiotic. especially about the nitrous. i know nitrous can damage a motor, but that really depends on the condition of the motor and the shot. i know turboed cars handle nitrous better and the gains are much better than that of the naturally aspirated motors. but i am new to spraying in a subaru. i just want to know what people think/know.
sorry if i wasted anyone's time with reading this new thread. i just want to do some minor work to my new car. not right now, im in no hurry, but in the future. and these are the things i cant get out of my head. i figured i would ask you guys first. I don't want to make mistakes.

thanks for any help/feedback.