Perhaps you could make the ui more like caesar 4, but I think we can live without a minimap. Make a vertical stripe on the right side and have the top list the region name and date, below that a graphical grid of buildings, possibly tabbed between military, civic, and econ. Below that you can list the econ info for the region.
Selecting units would put unit portraits where the building list would be, possibly scaling dynamically depending on unit count. Buttons for orders and formations relevant to the units could also display here. Same with buildings, select a building and orders or information relevant to that building pop up here.
I've actually grown to like the absence of the minimap, but would like better notification of attack events. Perhaps a red arrow on the edge of the screen in the direction of the event. The zoom levels are great, I'd just like one more in each direction.
I'd like a way to select only combat units. Like, holding alt while drag selecting units ignores traders/etc. I'd also like to be able to select all units of a type on screen by double clicking one of them. Extend this to buildings. Basically like a more traditional rts like 0 ad. Waypoints and rallypoints would also be nice.
Game is coming along great man, keep up the good work! I'm very excited to finally exit the chalcolithic. :P