My $0.02:
- Improve anti-lag (as many players coming from other RTS/Strategy games want bigger battles than 20vs20)
- Rework trading path for AI, maybe even allow for custom path drawing (if there is enemy CC between two AI allies, they will just send their traders right through enemy base)
- When AI is about to attack, it will always make a "build-up" spot, where most of army gathers (and pathfinder starts to sweat), maybe this can be improved?
- When AI garrisons tower/fortress, it is easy to move units back out of map visibility, so AI will force defenders out of the buildings, then kill then and capture tower/fortress
- Check if collecting game statistics (units killed etc) affect game performance, if it does then allow to disable collecting game stats
- Gaia ships on some maps hit very hard, it is not possible to achieve same damage per shot with any civ