Hassar - I don't think The Shaman read through the posts. He wasn't the original poster who challenged your child's imaginative use of skills, but he did hop on the band-wagon.
In response, I think it's awesome he can do that - my kids (now 20 and 16 (as of today)) have been playing since they were old enough to chew on the dice.
I guess I just miss the infancy of the game when player thoughts equaled character action, and a really good player could be brilliant and act like a moron, and a half-wit player (though rare - but did exist) could, after some time, really start putting the gray matter to work in order to bring themselves up above their normal operational mode.
Is it less imaginative that your son can incorporate the skills into his narrative, by no means, in some ways, it might be more so. However, it has been my experience (YMMV) that the reverse is the norm, where players have gotten so used to skill checks that they forget what that actions entail.
Some people describe the following scenario as "pixel bitchin'" but, it is now possible for a player to walk into a room and say I search the room - roll a die and either succeed or fail, without really thinking about what that search could mean. Meanwhile we used to walk into a room and have to specify what was searched and how it was searched - no rolls, role playing. I can see where both are appropriate and where a good DM would require the search check to be targeted, but RAW doesn't actually state it has to be, so in an imperfect world (and I think we've proved this one is) there is always some room for debate. (But then again around here I guess that's half the fun.)
BTW - My example was using 3.x skills, successes over failures is worse IMO as the rule just plays wonky...