Stuff like this is possible with the CK, but it takes lots of time. Current followers already make comments when you enter Dwemer ruins or come within sight of a creepy cave. The problem is that each comment is actually a hidden quest + some scripting. It isn't all that difficult to do, but it is time consuming. The CK as it is now makes it hard to enter your own sound files too. I've been slowly working on some followers styled after the companions in Dragon Age. It's hard enough just to get them to say a few lines of dialogue, let alone commentary while you travel. Slowly but surely, it's coming along.
