This is cool, but I don't know on what planet "C, Eb, F#" is a major chord. Seems to be off by a half-step (i.e. should be C, E, G)?
Yes, the major should be (C E G). (C Eb F#) looks like a C dimnished, though I think it would be better written as (C Eb Gb).
True - for some reason I have this affinity to certain notes being sharp and certain ones being flat (i.e. F# > Gb, but Eb > D#), even though the rule is that it should be consistent based on the key.