More robust, more functional camera options would certainly help matters. A revamped battle viewer is something I had thought was in the works ages ago, and frankly I'm surprised it's received so little attention. Was it one of Brad's little non-promise tentative roadmap items? Not sure where I got the idea this would ever happen (might have just been wishful thinking on my part) but the viewer has grown long in the tooth, no?
I also think there'd be a real benefit if GalCiv3 had a full-fledged battle arena mode. Star Drive 2, for all its flaws, has a pretty decent battle arena. It was indispensable, from what I understand, when some diehard modders came together and created the Community AI Improvement mod, which eventually made it into an official update. Coupled with a better viewer -- plus the workshop support that is supposed to be implemented with Crusade -- GalCiv3 might seriously improve.... with capabilities such as these all synergyzing nicely together! As it stands now, it's such a chore putting new test designs through the paces.
Having said all that, I consider Rog214 and Icemania's suggestions for fixing the ai's long lingering major shortcomings the highest priority. The suggestions here aren't far behind, though.