POC - really depends on the child, if they are ok with darkness should be ok, my son who went on it at 2 yrs old, got a little scared but was ok in the end.
Astro Orbitor - I haven't tried it with him, but only you really know your child.
Jungle Cruise - definitely, it's fun to watch the kids expressions when they see the "animals" they don't usually get the jokes and such anyway.
Universe of Energy - haven't been on it in years, probably yes though, although I hear it's long from some people
Dinosaur - NO, went on this and it scared me even.
Great Movie Ride - yes, you may have to cover ears and tell them close their eyes at the alien part, as my kids I had to do that with them.
Dumbo - my husband has taken my kids on similar rides and at 18 months my son hated it, he is ok with them now. My girls are just getting into these types of rides now at 2 1/2.