I think if anything the biggest change is not that civs aren't hurting specifically themselves in this, it's that no civs are getting stomped down early either through a failed attack or a failed defense, and by the later games there isn't nebuchadnezzar with 3000 points and the next guy with 1200, but a more even late game playing field.
Depends, you can have some hilarity ensue. They can all gang on one Civ (not the player), get their hairy behinds handed to them and make that one the most powerful (happened).
Or have them wield mighty armies that wield an even mightier budget that causes them to self destruct by deficit. And that army just dances on your borders and your single warrior just craps his pants every turn till you win a tourism victory (happened too)