The biggest loses are 1 through 4 on that list.

1 Reforms are an essential part of factions like the Romans. Without the script you will be stuck with you starting units only.

2 The AI needs to have the script activated or it will not get governments placed. Without governments it will take a while to build one on their own. And when they do build a government, it probably won't be right for the region and their recruitment will be screwed up. Without this script the game is pretty broken.

3 The AI will deplete their cities of people pretty fast. (Though without the money script it may not be a problem.)

4 The money script gives money to the AI because the game has been balanced to be difficult for the player. The AI can't handle this. Most likely the majority of AI factions will go into debt and stagnate until you roll over them. Without this script the game is easy-as/easier-than vanilla.