I would throw out a word of caution if the Headless Horseman is a top priority. They will not ride if the streets are wet (safety of the horse) or sometimes if the horse is spooked at all. I always advise at least seeing the Headless Horseman at the first parade just in case he does not ride for the second parade. Once he passes during the first parade, you can go to other things during the actual parade with lower wait times. Then you can see him ride again (hopefully) during the second parade!
Also, I recommend Villains Grove. It is such a visual and auditory treat! I also like that it is a little bit of a game to figure out which character each area represents based on clues in the music or lighting effects. The line can look long and stretch back to the GCH entrance/exit, but it moves very quickly.