Thanks to the change to the custom galaxy setting, we can now load custom scenario maps, like the ones which are used for the tutorials. Sadly scripting doesn't seem to work, but you can still make a map which gives you a different experience as the normal game.
I've made a small one versus one map with about 30 planets, 2 stars which is biased for the AI. The AI should be a considerable stronger enemy in this map since it has numerous starting bonuses and more planets at the beginning than the player.
Pirates on this map are also considerable stronger so you'll need to build quite a fleet to clear certain planets from pirates.
Unfortunately it isn't possible to force a starting location for the human player (it's random), so you may be in place of the AI empire instead. When you start the game you should only have one planet, an assorted fleets of frigates and cruisers, a capital shipyard and frigate shipyard and some other buildings, but no capitals. You get your first capital for free like usual, but you need some more fleet supports first (you'll be in the red with your starting fleet).
Download the map (it's called A-New-Empire.galaxy) and put it in the galaxy folder in your sins of a solar empire folder (C:\Games\Stardock\Sins of a Solar Empire\Galaxy for example).
Then start sins and when creating a new game, choose custom map, click on the wrench and select the map. On the right you'll see a bit of a back ground story for this map.
I suggest playing with marauders off and against a strong AI to maximize your fun.Download link.
-you sometimes start in the AIs place, making it too easy since the map is biased against the player, just restart the map if this happens
-I don't know how to make phaselanes to stars, so you can't reach them
-the settings for increased planetary structure don't work, so you'll start in the red with the fleet points unfortunately
PS. Don't try to rush pirate owned planets. Scout first or you could easily loose your starting fleet.