Before I stopped riding ToT - the bellhops really made the ride special. There was only one time when we had a bellhop who didn't seem into it - and even that turned out to be part of his acting, because he suddenly turned around and said something brilliant toward the end of his spiel.
For HM, it's a shame if they have to tone it down, but I definitely agree that they have less leeway than the ToT due to the younger ages of some of the guests. Some kids are already apprehensive about going on the ride, and they probably don't want those kids to be in hysterics before they even get in the Doombuggy.
I have actually never had a CM scare me at the Mansion, but I've run across some absolutely brilliant in-character ones. My favorite - last year on my birthday, as we were walking into the Mansion, the girl at the gate totally deadpanned "happy birthday. And deathday." LOL.