1) yes. There is an ally command that is part of the map commands.
#allies
specific AI will not attack AI
The player uses the nations numerically so #allies 0 2 means EA Arcos and EA Ulm would be allied
A number of the game types on Dom3Minions.com uses that to increase the levels of the game.
http://www.dom3minions.com/HostedGames.htm
2) yes. The #allai command-switch on a dom3 command line will create a game with all the nations of that era. The #superhost will host over and over without waiting for any turns. The #comptrn will generate turn files for AIs that can be brought up like your own turn files for viewing
3) abit more difficult. There was no easy way built in to see the whole map. But its one of the common features that players have built into the various Dungeon Master mods. My own (watcher.dm) creates a watcher nation which can easily and early cast the Eye's of God.
4) Again, not quite. The games keeps very little info from from turn to turn. With the DM mods you can see the map as the game progresses, and watch all combats. But to have play-back ability after the game is over you would need to record them.