actually its one of those games that works well SP. Give the AI some judicious advantages and it does ok at economic management, its got a bit better at naval war in the final patch and its ok at army stack building.
You have to avoid mercantalism in your own economic game play, its up to you to prime the world economy, maybe a bit of event scripting to ease some of the development burden (as an eg, you gain from other states properly exploiting their coal reserves)
since the core challenge of the game is managing your own state and gaining legacy - and bringing Perfidious Albion to heal, I've found it really engrossing played that way. Different to my views on the more military focussed games where in the end AI issues means that PBEM really is the best way to play.
AJE The Hero, The Traitor and The Barbarian
PoN Manufacturing Italy; A clear bright sun
RoP The Mightiest Empires Fall
WIA Burning down the Houses; Wars in America; The Tea Wars