I fail to see how the game will be unmanageable by turn 200 (much less around that long) with the ability to colonize any planet.
The victory conditions should be set to "by player agreement", and not with any of the bizzare settings.
Score is irrelevant. What if 1 player has 500% more than the 2nd place player, but there are 10 players allied against him? I don't think the game should end then.