That's outside the scope of this mod.

Probably. On normal, I tend to win on turn~ 120 with economic and can reach some of the others just as fast.
Economic victory cannot be nerfed by just changing the condition itself, its got more to do with how you can stack dust acquisition later on and how powerful acquiring dust is.
As mentioned, if you win economic by turn 80, youve already won since turn 60-65. Your change makes it so you by like turn 85 or something... but youve still already won since turn 60-65

On fast you can win by turn 80 if you know what you're doing

Might I suggest to not increased the Economic Victory Dust Cost?

The way economic victory works is.... you build yourself up, buy out multiple armies per turn if really needed and just need to spam the end turn buttons for 10 rounds. Spamming it for 12, or even 15, rounds makes no difference, you have already won way before that.