Easy v. Hard Scales?

I find that the scales in the major keys are very different in what you might call their 'playability', i.e. how they lie under the hand, how easy it sis to execute the thumb under or the third- or fourth-finger over when actually playing the scale. For example, I find Gb major to be one of the easiest keys, along with C# Major and B Major

Doug, I think the vast majority of pianists would agree. Chopin taught the scales starting with the ones you listed precisely because the fingering is easier to grasp and the hand lies more comfortably on them.

Yes but those Gb arpeggios are hard: you've got to twist your thumbs around on the black keys and still leave room for your longer fingers at the back.