I think the economy settings is a thing a beginner doesn't has to worry about. I played widelands for years without knowing what exactly these settings are about and what consequences they may have on game play. Today i know a little bit about them, but i can't say i understand the consequences exactly
My guess is that the initial settings are quite old and not adapted to other adjustments in the meantime. So i am all for adjusting them.
I'd rather suggest that stock setting could be decided before the game, as a preference setting. that would let anyone pick his own.
I am against such a setting, just because this would mean a player has to know what consequences they have. Having them as a preference setting would mean an advantage for good players and saves some time for them (because they won't need to adjust them during game play), which is also an advantage. So good players have two advantages if preference settings are implemented.
Instead of preference settings i would like to have other places to access them (not at a flag): Warehouses (including headquarters) and ports. I think having the button at those buildings is semantically better than having it at a flag.