If you are ok if it takes a couple of years, I could code it 

I have thought about similar things, but i don't know how to implement this... anyone with coding want to help out? I thought it would be neat if storehouses/farmsteads held "X" resources before they were brought to the CC, and if they were captured, the capturer would gain the loot of the resources stored before transferred to a safer place.

Maybe storehouses (or other dropsites, besides civic centers), should have a resource holding limit. So when a unit drops off at a dropsite, it stores it there, but it has a limit. You couldn't use the resources in the dropsite, but you would have to transport it to a civic center. Once it gets to a civic center, it goes to the bar at the top of the screen. There could be a wagon unit or some transport unit that transports (maybe 100 at a time) resources to your civic. It would be a like a usb hub, you have multiple devices plugged in, but it has to get to your computer to use it. The dropsite could also have a range, any structures in that range use the dropsites resources first, then the ones on the top of the screen (or civic center), then it wouldn't be like a usb hub as much 

@Asher Carthage has embassies because it's historically relied on foreign troops and technology to wage war (much like Saudi Arabia and UAE are doing today).

If Carthaginians have an Iberian embassy, shouldn't Iberians have a Carthaginian embassy. Also for the Celtic embassy