I wish it were possible to allow the game to run without a human player for a while. The way I play, invariably the AIs all gang up on me by 0AD and so I have to micromanage wars on multiple fronts. It takes forever to play. I wish I could let the game run itself for 3-5000 years and then take over one of the players at that point. I see no way to do this at the moment, but it can't be that hard.

It isn't: you can turn yourself to AI wih the /ai command.