haha, macster, you are a trip!
I believe S2 yields 265 HP with a 2-1/2" exhaust and a high-flow muffler.
Say you can add 2-10 HP for a good intake.
How much can one tack on for a tuned turbo/back exhaust? 5? 10HP?
Personally, my goal/expectation is to get 275 HP maaaaybe 280 out of S2 with a tuned intake and exhaust. (And a freak-in S2 release date already!

) If I can hold my own against a stock 350Z, then I will be finished. If not...I dunno....jump off that bridge when I get to it.
S3? Is that even a possibility or are we just dreaming? Will it be available before the V6 PT?
My unqualified impression on the whole smog thing is that you have nothing to worry about. Like 3Bar said, you haven't changed any fundamentals and the cat is still there. All you are doing is burning more fuel; will that fuel's exhaust still be catalyzed into CA happy air? Also, it is not like you are winding it out, under boost, and under a serious load when you get smog tested (unless they changed it since I lived there), so all of this performance stuff is a non-issue, yes?
CA is a nice place to visit (live for a while), but I would not stay there. If the Governator were to be there long enough, that may change.
OK, now for my n00bness; I must ask: What/who is this PVO I keep seeing in posts? [:I]
Also, what is a "race pipe"? Just a straight pipe, sans cat and muff? (baha, funny how that sounds like...oh, nevermind)