The one thing about economy in adventure mode is that money is currently just broken and it wasn't always that way. I forget exactly when it got broken, but there was a time that you could sell items for coins, buy things with coins and everything would work the way you expect. It would be nice to fix it at least to the point of being able to use coins freely for everything.
There are also weird rules about stealing things and what it means for something to be stolen. If I remember correctly, it *does* affect your reputation (though your reputation isn't really used for very much at the moment). Making that kind of stuff more visible and also making it operate in a way that seems logical would be nice.
Finally, because I play with "thou shalt not steal" house rules, I tend to barter for armor and weapons that soldiers are wearing (giving them the bounty of my bone carvings). I kind of feel like it would be nice if soldiers wouldn't be quite so accommodating though (walking around naked holding 42 badly carved bone carvings after meeting me). It would also be nice if the "value" of goods was a bit more random. I once RP'd a silk trader, buying silk at one side of the map and selling it at the other. But I could only barter for essentially the exact same value each time, so there was no sense of profit. Just useless activity. Even if it were random, it would be a lot more fun.
I should make my way to the suggestions thread :-) But anyway, I think the point that there are some pretty small tweaks to adventure mode that would make a big improvement is well taken.