I did the Royal Family 5k last Feb, which was my first race ever. I didn't stop for fear of being swept and what I thought were long lines. In hindsight, now that I have done the TOT race, I could have stopped at least some.
Rapunzel was the theme and she and maybe her prince were outside near the corrals before the race. The line was long, so I skipped it. When we got done, we headed back over there and the Prince was there alone. When we were done with him, they said that Rapunzel was coming, so we got back in line and waited for her. Much shorter than before the race. They also had her horse there for pictures.
During the race there were some rare characters, though I can't be sure who I remember seeing. I "think" Mulan, her prince, and Mushu. Snow White and a one of the dwarves, maybe. I think Genie, Jasmine, and maybe Aladdin were there. Mickey, Minnie, Donald, Goofy were probably there. I don't remember if they had special clothes on or not. I'm sure I am forgetting a few.
Anyway, yes there ARE characters on the course. I haven't run the Princess yet, so I can't say if they are the same ones you will see the next day.
I do agree with the PP about the characters making a big deal about the medal the next day! I went on a character hunt, since it was my first race ever, which I ran nonstop (not planned, but if you don't stop for pictures, you just keep going). I was so very happy and all of the characters made a big deal about it!
