Yet another question about reforms

[MarcusAureliusAntoninus]

What does the script activate though? I know the season cycle and probably the rebel city diplomacy system also the reforms of course but anything else? traits?

The two big things that the script activates is the financial assistance script and the AI government placement script. Without these two things, your game is almost broken. Without the financial script, the AI will go broke in the first turn and never recover. Without the goverment placement, the AI won't have governments placed where they should. (They will be able to build governments, but not the governments they are supposed to build, only what you can build, even if it is there homeland. It will take them years to build these incorrect governments, if at all, and will thus be unable to recruit the units they are supposed to in any conquered region.)

The script also activates the four turns per year, the reforms, misssions, AI city interactions (like Karthage declaring war on Roma when Roma enters Sikilia), and a few traiting deals.