At first the idea of having a kid read that passage about Esther made me mad too, until I realised I had let my young boy watch a kid drama about exactly that passage just the other day on a kids channel.
As far as pressure goes, I doubt the kid has experienced anything but joy in doing this. He is obviously exceptional. The sad times will come when he is older and trapped in a cult. I was a very bright kid myself, and was very young when I gave my first talk, but I remember it as being fun. My mum and I made a big poster that was a storyboard of my talk and I had it up on stage. I was very proud and everyone made me feel special. Of course I went on to become an attention seeking child, but I think I am that way inclined anyhow.
The kid will hopefully break out of the cult and do something with himself when he is older. He is obviously very smart. Teaching your kid to read young is a great thing, especially for a JW child, the sooner they can read the sooner they can read JWD!