I often find myself looking for information and spending an inordinate amount of time trying to calculate things. I realize this is a personal preference so it may not be of any value to the developers but I would like to see a quick reference tab or section of some sort that gives me all the vital information for my empire and fleets. I think this would go a long way in facilitating an epic feel. Additionally to be able to see general data stats in real time for my empire as well as others if I have relations with them would be a great thing. This would include all diplomatic and military relations.
Moreover I really want an encyclopedia function built into the game with all the general unit info as well as techs and bonuses organized by race and category with visual examples when possible. This will also augment the immersion and epic feel at least for me. Additionally a user stats section with lots of data organized by race would really add value for me so I can track my progress with each as well as a section for multiplayer data. I also think such a thing would be of real value for the developers when work begins on the X-pack to be able to get this data from players should they chose to send it to you.
I always play the game at ultra high resolution (see below) so I have lots of room for displaying stuff. Thus I would like to be able to move elements of the GUI around and save those preferences.

Regarding resources, I think a system where the more a player has of something the more likely that player is to incur a pirate raid(s) separate from all other in game reasons for pirate attacks in the current build. I also think that all damage value should be added to the pirate side for additional ships. That way the system is self sufficient and can scale to some degree.
On the tech tree I would like to see some techs that require total control of a star system and more than one. Moreover some tech that gives bonuses to specific fleet composition and ship levels would also go far from an immersion aspect specifically.
I'm also on the fence about the total economic aspects of the late to end game play on large and huge maps. As I stated in my prior post there is this build up then a hollow let down. Granted this situation may simply be because the beta does not have the full tech tree and what not but I get the distinct impression the system was designed for small to medium size multiplayer games that would last in the one to two hour range. Now I'm not implying that is bad in any way but it does detract from the epic sense for me. Accordingly I believe there needs to be new dynamic introduced that is designed to come into play either automatically or after some specific conditions are achieved specifically targeted for large and very large single and multiplayer games. This dynamic will add to the epic feeling considerably. This is especially so if it can only come into play for such maps.
Another personal preference would be the addition of random events both general and race specific as well as for individual players. Such things add so much to game play value and immersion in my opinion.
The ability to trade or make peace using relics would also be something nice on the diplomatic front at face value. However given that element of the game is highly crippled now I don’t know if such a suggestion would be viable.
In general I would like to see the tech tree scale in size and cost with the number of stars or even planets for that matter.
Regarding the AI, I think AI players that are of the same race should have an affinity for developing alliances with each other and an aversion to relationships to others.
Addressing what amounts to my biggest peeve with the game, I would like to be able to set an auto retreat options for ships especially capital ships based on damage and distance to retreat jump area. I have lost so many high level ships because I simply can't click on things fast enough and accurately assess situations in the seconds involved in large battles before ships get to the point of hopelessness. This is especially frustrating when there are several battles going on at one time in different systems. If anything is going to turn me off from wanting to play this game this is that thing.
On the topic of capital ships, there should not be a limit on capital ships for purely logical reasons. I believe there is a better way to handle this limitation by design. I think a serviceability or some maintenance variant cost that increases based of total capital fleet size after a specific number of ships should be used instead. Such a system would allow for several large fleets for very large game maps.
There is more but that is all I have time for now.
@TGE - As I stated in my PM I think in numbers so much the concept of economies of scale seemed a highly appropriate term to use given the intent of the topic and its relationship to optimum production value excluding constant returns and diseconomies of scale as applied to the general game mechanics encompassed within the static economic model. I guess economies of scope could be considered more appropriate.
Nonetheless, creative usage of language is the foundation of dynamic change for something we consider "living" and paramount to our success as a species. Anyway, thank you for the compliment.