In galciv1 when a game is loaded it gives a short summary where the player is (ie technologically falling behind, not in war with any major civ, etc). The journey starts today in galciv2 is poorer.
The planetary defenses should be extended, introducing structures that can provide attack and defense assistance to orbiting forces similar to a military starbase and also more (level of) structures providing defense bonus for the planet.
The higher up economy buildings should be renamed, in galciv1 one per planet applied to all and having twenty stock exchange on a planet is a bit funny. I think the Iconian tree is better.
EDIT: The GNN should be able to use the scroller of the mouse.
More for galciv3 than an update:
Again in galciv1 the actual output depends on the population, in Haegemonia (IG1, IG2) the buildings can be used if the population level is sufficient. In galciv2 if you capture a full factory world it will be up and running even if you have only a few surviving troops or after a virus attack.
Social production should use unused military capacity. And/or the military/social/research slider should be set on planetary level.
The major / minor civilization concept might not be needed. Why are the Iconians "better" than Carinoids?