Good points!
Of course the even better option is to let someone else do it and co-drive the car.

Ash has just put Konis on his, but I'm don't think he has the time (Navy) to be truly serious with the car right now, so I doubt he's planning on a full stock class prep (i.e. FSB, wheels with A6s, etc). I believe he's thinking of just having fun (AD08s so street tires at an autox).
He was so damn lucky to stumble across the car that the dealer didn't know was different from a 996 (and even then bought the thing for a lot less than one would think).
Anyway, I'll get a chance to co-drive the car at some point which will be very interesting. I drove the car from Atlanta to Raleigh and had it here for a couple of months last Spring, but I never pushed it at all. Other than that experience, the only other time I've driven a 911 was in 1977 in a 1976 911S. The only autox experience I have in anything other than front engine, rear drive cars is from a 914 circa 1975 or so.
It should be interesting. Jackie co-drove it a couple of weeks ago at a BMW autox down in Atlanta, and she did really well, surprisingly well. I think her progress as a driver would have been even faster to date with a dialed-in suspension STX car or whatever as opposed to dealing with a pushing stock class pig E46.
Since there are only 1964 of these cars, I would assume at best it would be good for a one-time success as you point out.
Switching gears, if you were going to pick one car to simply have a heck of a lot of fun with for the next 5-10 years...street driving on rare occasions, autocross whenever you can (no pretense of nationals), throw in an HPDE every now and then, etc, and you want an SS-class car -- what would you think?
996 GT3? Z06? Elise?
Alternatively, if you were thinking AS, how uncompetitive do you think the E90 M3 would be in that class? I love the S65 V8 (wish it had the torque of the E39 M5 S62 though), and it will be the LAST of the high-revving, rip your a##, M-engines from BMW. With the pins out, you can get about -1.7 degrees camber up front (I know, not enough), but the other aspects of the car (4 doors, fold down seats, etc) make it extremely practical. (here I'm thinking how Tia wouldn't mind an E90 swap as her car approaches 80k miles, and I'd just steal her car to autox).
I'm blabbering here, but I'm trying to put my finger on an autox/fun car for the rest of my 50s.
Chuck