I'm a little bit confused during the dream. Littlefoot starts off with the gang. Then Shorty is in the group, but Littlefoot isn't? Then while everybody else is on the Great Wall, Littlefoot is walking by himself? It kind of seems to me that you meant to have Littlefoot on top of the Great Wall, not Shorty. Then again, I could be wrong.
One other thing I noticed. Some of the language the characters are saying I don't believe they would know. As far as I know, there is no Jesus or God in that universe, so I would be careful about things like that. Then again, I might be guilty of this as well in my fanfic, but just food for thought.
I'm not entirely sure how a crossover like this would work, but it certainly does seem interesting. If you can pull it off, then by all means go for it.