In a pure sense, no, there is no way to simply "win" with money alone.  In a practical sense, if you have a substantial economic advantage your victory in the long-run is assured anyways.  You could pull off superweapon spam with sufficient economic advantage, and in a battle of attrition you're going to crush the enemy anyways.  Certainly in team games online it's very difficult to lose if you have one player with a super-massive economy that's fuelling the others. 

I always go for super-economy in large multi-star scenarios (provided there are no enemies in close proximity, of course).  If no one puts pressure on me, I can easily have over 100 creds per second by the 1.5 hour mark (regardless of start position), and my first superweapons are up by the 2 hour mark.  I've had many players simply quit once they realize I have an economy to fuel superweapon spam.  Actually it's the primary reason I don't play multistars anymore, because strongest economy wins hands down if you don't/can't rush.

multistars are the judge of a true player.

I thought having all the ladies love you was the judge of a true player.

Perhaps you can mod the diplomacy in the game and make it so that you can buy favorability with other empires through monetary donations. Thus, you can form a peace treaty with everyone. You could also perhaps mod the pirates somehow and use the bounty system to win (perhaps you can unleash multiple pirate raids at once).

I'm looking forward to the diplomacy expansion .

hmm. that made me think.

LOL so it's come down to "your mom" jokes.   hehehehehe