I think the most important things that allowed us to get so far ahead were:
1. The most streamlined resaerch path, beelining first towards Optics, then towards Astronomy, carefully calculated in advance use of GP to lightbulb techs, etc. This saved us a great deal of beakers and allowed to expand really fast, while still getting Astronomy and samurais ahead of everybody else. I think nobody except us did that, even team Peanut had to waste time researching useless Philosophy.
2. The early focus towards moving the Palace ASAP and eliminating Spain. We were not the only team to do this, but nobody killed Izabella as early as we did as far as I know. Well, religion definitely helped here with faster overall expansion, but it was not only religion. We were really focused on this and hit Izabella early and hard, putting all our production into swords and chopping all the forests we could reach. This way we grabbed some great cities for our empire early and had time to fully develop them before invading the other continent.
3. I would place religion and our strong start only 3rd in this list. Both luck and the decisions we made. Failing here would have still kept us on track, but without #1 and #2 we would not have achieved anything.
4. Micromanagement. Some people believe that winning GOTM is about crazy micro. I think it is not nearly as important as long term planning, but it definitely played its part. And building chariots to be able to whip citizens all the time was a really cool idea.
