Long story short: I bit off more than I could chew.
From the start:
In some test games, I was disappointed that Dogs did badly against Archers in cities. Then I discovered that by going Bronze Working first I could actually attack with a Dog before the AI had Archery! So that's what I did. Leading to...
That Dog had to kill three Warriors to get there but he made it! Then he went on to kill another Warrior from Roosevelt, kill another Archer, and in the process take two more cities. And steal three workers. A super-Dog indeed!
Then I expanded peacefully for some time...and then a bit later I really wanted to get a religion and Stonehenge, both of which Cathy had, so I made about 10 Swords/Dogs and took her two cities. By 1100BC I had 9 cities, by 500BC 12.
The problem? I wanted a space victory...but I was COMPLETELY broke with all those cities (no city razing is evil). Conquest money allowed some research, and here I made a crucial mistake. I got Writing, Masonry and the Oracle techs to Oracle Aesthetics, planning to keep the economy going with a lot of wonder failgold (thanks WastinTime!). I got some failgold from Oracle as well. However, this doesn't work at all if THE AI IS TOO SLOW TO BUILD ANY WONDERS! At 1AD I surely have more than 1500 hammers invested into Temple of Artemis (plus some into Statue of Zeus/Pyramids/Parthenon/Shwedagon Paya). It only requires Polytheism! But nobody builds it, and so I can't research anything which would give me a way out of this crisis, like Currency or Code of Laws. I'm far too deep down in this hole to ever get a decent date. If I would have aimed for domination or conquest this would have been a great start, but as it is...
However, I find this game still to be a lot of fun. I like the setup! It's a pity that the espionage aspect of it doesn't really work, since AIs seem to spend their Great Spy immediately on a Golden Age on the first turn of the game (even the barbarians had one already!) instead of using it for an espionage advantage. Not that anyone would already have Alphabet of course...