I thought about this a while ago, and came to the conclusion that there isn't really any way to determine one's skill level with pre-defined challenges.
My computer is pretty old, and can't run NASSP (or SSU). By the standards Tex proposed, I could never qualify for "expert" status, but not through any lack of skill on on my part. I certainly consider Flytandem to be an expert at many things, but AFAIK he has very limited experience with the XR or DGIV - I can probably re-enter tose vessels better than him - but no one else can plan and execute complex multi-sling trajectories as well as he can. The guys who came up with the LRO-LCROSS add-on certainly qualify as experts as they figured out how to fly that mission using both IMFD and TransX together. But for all I know they can't re-enter a XR-2 with an unpowered landing. I'm not saying they can't, but I don't know, and even if they can't they still qualify as experts IMO.
I call myself advanced, but don't feel I qualify as expert partly because I can't use TransX. I'm better than most with IMFD, winged ascents, re-entries, etc, so some would consider me expert.
In the end, I think it's much more important to know your strengths and weaknesses. I seem to have earned a reputation for giving good advice, mostly because I only give advice on subjects that are my strengths. I don't give advice on how to use TransX, because my advice wouldn't be worth much. I do give advice on IMFD, because that's one of my areas of "expertise".
Even in the areas where I excel, there are others who can better me. Should only the best person be an expert? Where do you draw the line determining what's "good enough" to qualify as expert?
I do feel that skill developing is separate from skill flying. Martin, by his own admission, is not the best pilot around. I easily beat his score on Lua Challenge #1. I should hope so - I spend my time flying, while he is busy developing and doesn't get to fly nearly as much as I do. He is certainly an expert developer, while I don't even qualify as a beginner dev. I certainly could never develop Orbiter, no matter how long I spent learning programming and advanced math. I suspect that if Martin had as much "stick time" as I do he would be equally skilled, likely superior.
I don't have anything against some "guidelines" for determining skill. I've seen people here call themselves "advanced", even "expert" when they demonstrate a skill level I wouldn't even call intermediate (rely on "unlimited fuel" to get anywhere, etc). The guidelines should be "general", and not specific to any particular vessel, vessel type, MFD, add-on, etc.
It should allow for "specialists". Someone who specializes in the Shuttle may be expert at launch and ascent, rendezvous, docking, re-entry, yet never have gone beyond LEO. Another who specializes in unmanned exploration could be capable of planning (from "scratch") and executing missions as complex as Cassini- and have never docked or re-entered.
Just my opinion, of course.
An advanced user is flying everything that can fly (and sometimes even flying bricks like the venerable Space Shuttle or Buran), doesn't crash or burn or forget to extend gear, can navigate an ICBM in a suborbital trajectory with CEP of 3 kilometers or less, doesn't ram space stations, has visited all planets and dwarf planets of the Solar System, has built bases on all the moons of Jupiter and Saturn, can perform RTLS in a Space Shuttle Ultra...
" level experience with Orbiter anyway, a standard us mere mortals may aspire to but never reach.
