That seems to be that case. The Satellites tech and 2xAttack Amphibious unit ability, for instance, they have been requests on this forum for a while. Clearly someone is listening --although those are two fairly obvious additions to the game (not to mention that the first was already present in Civ2) and did not really require player insight in order to develope them.
It would be very interesting if personelle from Firaxis or Atari were to post replies to requests made by players, as it would clearify what is and what is not within the scope of Civ3's engine.
For example, I recently posted a thread concerning Individual Unit Maintenance Costs. Although this would be a significant change the game's engine and gameplay, I would be interested in finding out if such a change would meet Civ3's requirements and if so, how?