Lazy Knight
Chieftain
I've actually been thinking about making a total European Medieval mod. From the Fall of Rome to the discovery of America with Charlemagne, the Crusades, Hundred Years' War, Wars of Roses and all that in. Then I'll need a big Tree though, for I would want such a game to last long.
What I think would be a great thing is some kind of "medieval framework" modframe.
You see - If somebody wanted to make a mod on, say, the crusades he would be starting where you started. He would have to make a map, rename the factions, place them on the map and have a beta, but would face the same problems you did: Tons of unfitting wonders and buildings, long build times for units, too fast teching/too few techs and a total of like 6 fitting units (Crossbowman, Knight, (Horseman), (Swordsmen), Longswordmen, Trebuchet, (Pikeman), (Catapult)).
So you have fixed most of that already and are working on the last issues. If you packed that without the map into a mod, you would propably help lots of Modcreators to kick-start their mods.
I had been planning to do this myself for the classical Era, but I currently lack time and hence the modding skills