270 is all you will get in 1460. I wanted you to experience a city check.
Immediately after city check, you will get 368. If you start checking advisors, (F1 and F5 come to mind) caravan payoff drops back to the 270 range. To keep the payoff high, I don't check the advisors.
(Some are OK, but I leave that as an exercise.)
When you go through city check, you will see the pollution bug in all its glory.
London and Babylon do not attack because the clock still says BC. I have put transports right in the path of a Babylonian ship and it just turns around. There appears to be no inclination to attack until 1 AD. I gave them automobile deliberately - to slow their progress toward railroad. When they get railroad, the caravan payoff drops by 50%.
I do not have a license for TerraForm. The game is all reload, fast settler and ship sentry. It takes four passes of reload (with fast settlers) to clean up all the pollution from one turn, for instance. That's why everything looks clean.
When I started this, my goal was to beat my previous best science score - somewhere in the low 800's. After seeing how well this game has developed I started shooting for future tech 900 by 20 BC. I am now toying with the notion of future tech 1103 in the early 1500's AD.