I LOVE this idea! It's literally just what I was thinking about for a Fallout game. Great minds think alike I guess.

What the OP is talking about is of course a "true" sandbox game -- a game where you can influence the world around you and a script causes a realistic reaction to your every action, which - if made close to perfection - would give the player the illusion of really living in the Fallout universe, with disbelief thoroughly suspended. I'd love to see such a game too... sadly, I don't see it happening within the next ten years. There's simply too much content, too many scripts, too much worldspace, etc etc....

But I'm absolutely sure there's going to be such games in the future -- and hopefully I'll get to play them when I retire or something


Edit: Deleted sentence


EDIT:
Oh yeah, here's what I was originally gonna post, but it kinda hid somewhere in my brain while I was writing the other stuff (this happens a lot)
The problem with Fallout and Oblivion - if you see lack of sandbox features as a problem (as I do) - is that they're ACTION RPGs, not clean RPGs. This means the developers are gonna focus on making the games attractive to both roleplayers and trigger-happy mutant killers. Cooking, using the toilet, flushing the toilet, sleeping every day, eating every day, etc etc, IN GAME, is just too tedious for most players - therefore it's left out of the game. You've got The Sims for that, but it just isn't the same, is it?