One of the biggest differences to gameplay is the removable of the requirement to get a certain cocktail of shares before the surprise. I felt that this was unfair and ruining replayability. The map is now winnable on every attempt even if you don't know anything about the surprise.
Other changes include some optional challenges for victory points later on in the game that should hopefully keep the player engaged further into the game. I did raise the points required by 10 in light of this. More than 10 extra points are available with the new schemes. Let me know if it's too much.
I have attempted to make this for players of all abilities. I'm sure there is an error or two in the coding so please feel free to try to find it!
One thing that I'm not 100% confident about is the AI strength later in the game. I added some events to penalize them if they do too well, but some of this depends on the skills of the player and how they choose to interact with the AI. Any comments/suggestions on this line would be great.
Final note: I didn't touch the seeding preferences, buildings including mines, agricultural communities, and logging camps are being seeded onto the map normally. If you don't have much of one resource on the map at game start, it will show up within a few years.
Edited: updated map file.
Have uploaded the corrected version.