All we want is a taste of the game - a feel for the controls; a look at the interface; maybe a taste of the interaction with the world, perhaps a smattering of combat. It would be a hell of a lot better than nothing in my view.
I'm all for a demo but most of those things you mentioned can be found in videos quite easily. In the case of RPGs I actually want a very representative demo because so many fall apart after the finely polished tutorial stages. I've watched enough videos of Borderlands to know I'm going to love this game, guaranteed purchase even with a lack of a demo. There's plenty of material online if you want to take 5 minutes and have a look. It violates your personal no demo policy but I think in the end you will be happier with the results.