John Picard wrote:
Spock is probably a commissioned officer with some teaching duties, hence the grey uniform (instructor) while in the Academy.
Not perfect, but I like it,
Remove the word "probably" from your statement. He designed and teaches the Kobyashi Maru plus he was Pike's first officer. He is much older than Kirk and as such had been a Starfleet officer for quite some time.
Spock doesn't Teach the Kobayashi Maru, since Kirk did not know who he was at his hearing.
Kirk: Who is that pointy-eared bastard?
McCoy: I don't know, but I like him !!!
He did programming for the Kobayashi Maru test for the simulator, and may indeed have been the creator of the test, since nobody established where or when it was created.
Spock probably also has a fair amount of field experience, and is already First Officer of the Enterprise under Captain Pike while working as a technician at the academy.