I'll do my best to help, but I don't have any kids (just younger siblings and watching other kids at the park react).
Magic Kingdom
Country Bear Jamboree -- not too scary, giant bears that sing (nice bears), is a little dark but not bad.
Enchanted Tiki Room -- cute show, a little loud, lots of birds that sing and the birds from the Lion King are in it.
Jungle Cruise - This ride used to scare me because they used to have a fake gun that they would try to shoot the animals with (it was LOUD to me). However, I *think* that they don't do that anymore, but am not sure.
The Many Adventures of Winnie the Pooh -- great, fun ride for kids.
Mickey's Philharmagic -- another great ride. It's in 3D, but it's all very cute from the Disney movies (you fly with Aladdin, etc.). One of our favorites.
Peter Pan's Flight -- I always really liked this ride. When my brother was little, he was afraid of the crocodile in it, but I always loved it. It is a little dark but a great ride.
Pirates of the Caribbean -- There is a part of the ride where it looks like the entire town is on fire. When I was little, I thought the town was actually on fire. There is also a part where the ride goes in between two ships that are firing cannonballs at each other. It is a little dark and has one small drop.
Snow Whites Scary Adventures -- I wouldn't ride this ride when I was little because of the witch in it. It's not really that scary though, maybe a little dark. I prefer Peter Pan to Snow White.
Splash Mountain -- GIANT drop for the younger kids (you'll see it). Inside, it is very cute with all the characters. If you can handle the drop, it's a lot of fun.
Stitch's Great Escape! -- I have been in this ride lots of times where the younger kids are screaming their heads off. The lights go dark and it feels like Stitch is breathing on you and spitting on you. You also have these harnasses that go over your head and so I think that is a bit intimidating for the younger ones.
Epcot World Showcase
Mexico boat ride -- cute ride. If you can do small world, you can do this. I can't remember if there is a drop or not. If there is, it's not a significant one.
Norway Maelstrom -- a little bit scarier. There is a troll inside and at one point, the boat goes backwards and you go down a hill. I think this is probably the scariest boat ride. The older kids should have no problem, not sure about the younger ones.
Epcot Future World
Honey I Shrunk the Audience - Most kids like this ride, but there are some scary parts. If you are wearing shorts, it feels like hundreds of mice are hitting the back of your legs. There is also a giant 3D snake and lion I believe. I personally think it is one of the scarier 3D movies even though it is one of the older ones.
Universe of Energy - don't know.
Hollywood Studios
Backlot Tour - It's been a LONG time since I've done this. I think the worst part is Catastrophe Canyon (if they still have it) where a fire breaks out on a truck and then the canyon gets flooded.
Sounds Dangerous - too long since I've ridden it.
The Great Movie Ride -- we rode this last time we were there. There is a little bit of a scary part where you go through a scene from Aliens. Also, there is the witch from Wizard of Oz. I think there might be two versions of this ride. In our version, there was a live actor that was a gangster that took over our ride vehicle for a while.
Indiana Jones Stunt Show -- too long since I've done it.
Lights, Motors, Action! Stunt Show -- not scary that I remember, but it is loud.
Muppet Vision 3D Studios -- cute show. As long as the kids don't have problems with 3D movies, they'll be fine (you can always tell them to just take their glasses off if they do).
Animal Kingdom
It's Tough to be a Bug -- I personally don't think it's that scary, but I've seen LOTS of kids that are scared half to death and are screaming their heads off to the point where their parents would have to leave the theater. There is a part with the mean grasshopper... I can't remember what else they were upset about.
Kali River Rapids -- I haven't ridden it, but it is a circular raft ride.
HTH! I know some others will give their opinions too!! I'm sure a lot of these rides will be fine with the older kids but a bit iffy with the younger ones. Although, I remember with the Haunted Mansion especially, my younger brother would ride that before I would (and he's 7 yrs younger than me!) so it just depends on the kid too.
