that's a great analysis, i like what you're doing there.
Yes, it's time to do a background with a pumpkin and a cat?

Sure fire, popular and covers all the favorites.
Never repeated enough, yes, two months is not too soon. I just sold two Christmas images last week on Adobe. Someone bought cards on FAA.
Last year I hit Halloween hard and Thanksgiving too for the illustrations. Not much activity. I'm hoping that this year, they will have aged well and will lick up some action.