How can you possibly start teching that quickly? I just don't understand how you are able to maintain such an empire so early on without courthouses, with a military that could take over so much land, and without falling back on tech? Especially on levels Noble & higher
blitzkrieg1980,
You answered your own question. I DID have courthouses and I DID have a military that could take over so much land. Praetorians are Overpowered almost as much as Quechuas.
The way I managed my empire's economy was a start from a Trade Route Economy into a Religious Economy and will eventually push into a Specialist Economy.
I start by making sure I grab the Great Lighthouse. Since most every city in Europe on the Earth Map is coastal, that's +2 Trade Routes in every city. That'll nearly triple the amount of Trade Routes I have available to my empire! From there I target Writing if I don't have it already. I then open boarders with everyone I'm not planning on warring in the near future for a slough of foreign trade routes. My next tech goal is Currency. I get Mathematics to tech to Currency, not Alphabet, because I want to get the Hanging Gardens up and running quickly, and usually I can trade Math for Alphabet, or even Aesthetics for Alphabet because I'll be going there shortly. Anyways, I'm off track.
After Currency, I usually take a look at my empire and decide how well I'm doing. If I really need it, I'll head to Code of Laws next for Courthouses. Organized means cheap Courthouses, so I can whip those fairly quickly.
After Code of Laws, I usually head up the culture branch (that's what I call it) for Music's free Great Artist.***Side Note: Usually by now I know who has which holy cities, and who has been spamming their religion around. At this point I started to prepare for my future religious economy, even though I didn't have any of the wonders necessary for it, I wanted to be prepared.*** I then research Meditation, Priesthood, and Monarchy and squeezed Monotheism for Organized Religion since I am focusing on spreading the soon-to-be-conquered religion around. Now I can bulb Theology. If I do found Christianity, great, if not, I really don't care. I want Theology for the AP for the production bonuses of my buildings. This began the start of the Religious Economy.
Construction and Calendar, came soon after, but I knew I needed Divine Right, and since I had Theology, I spent about 20 turns on Divine Right so I could get the Spiral Minaret fairly early. To be honest, it was probably in the late BCs (I think 70BC) that I finished the Spiral Minaret. So it wasn't like I had it in 2000BC, but I still think building that wonder pre AD on Prince as quite an accomplishment.
Next I picked up the missing Engineering, then I B-lined towards Banking for Mercantilism to move into a Specialist Economy. Soon after I'll be targeting Paper afterwards for the UoS, before I pick up Civil Service, too.

Lets recap:
Great Lighthouse + Currency + Open Boarders for a Trade Route Economy
Target the nearest and most spread holy city's religion, convert and spread the religion accordingly.
Focus on Theology, Divine Right, and Paper for the Religious Wonder Trifecta (AP, SM, UoS)
Banking = Mercantilism = tons of beakers with a huge empire.
And from there, it's pretty easy.
The one thing I didn't do, which I'm looking back on as a mistake was not utilizing the resource-trade-economy. I don't know if this is the real name for it, but that's what I'm going to call it.

A little bit here, a little bit there, a bit over here, and a little bit from over there too adds up to a lot in the end.