POTC isn't scary at all (unless skeletons freak you out...lots o' skeletons in that ride!); as others have said, the drops are small & at the beginning of the ride.
The Indiana Jones ride can be scary, but mainly because of the things that jump out at/come towards you (a giant snake, skeletons, the "rolling boulder" at the end). The ride is pretty jerky, but less so than the Matterhorn & slightly more so than Big Thunder Mountain. It's mainly the atmosphere that some people find frightening, not the ride itsself.