i started another with Ada/Maya, taking only the +1 exploration +1 diplomatic cards (my standard ones), to see if the previous game was a fluke or if I started it on the wrong difficulty. It was apparent that it was not a fluke, this time I started in the center east of the map with Frederic/Egypt directly north of me, Tecumsah/Maurya to the SW, and Lafayette/Rome to my NW. This time I had iron working before they attacked me, so the war went about as well as could be, took one city from Frederic, everything except Tecumsah's capital (multiple walled tiles on an island, impossible really in Ancient Era), was building my 7th and 8th wonder when the age ended, but got all the other paths, and ended on 13 settlements because I settled 3 on the last turn for a +1 culture point quest. 4 cities with Maya's unique building, so that will result in domino during ensuing ages. Did both Future techs (2) and a Future civic. Same basic start with civics, got discipline late then mysticism but it didn't seem to hurt, could defend against city states with 2 hulche. The nearby friendly scientific city state helped, as well as getting Layfette on my side with 2 cities having gold, I had 2 more so purchases were very cheap. I can see how the rest of the ages will go, so I will stop this game and try something else next time.
One thing I have noticed is that the AI settles their cities much later now, the second city is pretty quick, but they are very late to cities 3 and 4.
13 settlements, wow, unhappiness must've been rife!
I'm not sure you'll experience such smooth sailing after transitioning to Exploration when so far above the cap, unless you've got some serious happiness boosts from somewhere...
Did you do all this on Deity? It almost sounds too easy!