Hook's Pointe is a rather nice restaurant. I would take a well behaved 5 year old along but it is not a meal designed to cater to the average kid that age. It is not going to be a Captain Hook experience for him, but a fancy restaurant experience which he may or may not enjoy. (My little weirdo adored nice restaurants at that age but not all do.)
If he wants a meal where he might see the captain, try Goofy's Kitchen. If you want Peter Pan theming, try the pool. Below are some good reviews. It is not Kid Unfriendly but it does not go out of it's way to cater to the little guys either.
Yikes -
We met friends for dinner there last August - 4 adults, an 11 year old and 2 8 year olds - the kids were bored out of their minds! I didn't think that the food was good - certainly not for the price that we paid. And we are the type that don't mind paying a lot for a good meal - this was NOT a good meal! Service was okay, but not great, and the place looked a little run down.
Sorry to be negative - Hook's Pointe is the ONLY restaurant that we didn't like down there!
I think that there are better options for a 5 year old! Good luck!