ExtremeMod was tested almost exclusively on Noble, and on Epic speed with Aggressive AI and Raging Barbarians.
You would be the first to play on Settler as far as I know. Anything at the level would have been simply be the stock settings of the previous Mod (Thomas' War) or even the vanilla settings. I really see no point at playing a game at such a simple level that it offers no challenge, and I cannot give any strategic hints.
You have made allot of comments but I will touch on a few:
My Advice -- don't use automated workers. I will look at why they do that, but you are losing so much of the game by automating things -- there is no race, so take your time and use workers sparingly and effectively.
Try playing on Noble (and Raging Barbarians) and without the Great Wall to protect yourself (you will see barbarians and plenty of them). That is how the mod was designed to be played!!!
Don't play the game on Normal speed. Play it on Epic.
I am unsure where you are seeing the -7% unless you are looking at one of the traits for a specific culture?
Steam Power created a cultural environment dependent on carbon (coal, wood, even fossil fuels to a less extent) fuel sources to such a degree that life during those times was quite unhealthy. The Era of Steam was the most unhealthiest times to live -- look at 19th century England for examples of the miserable living conditions.
Wonders were picked up from the previous Mod, but I will take a look at them.
Overall, you need to really step your game up a bit. Its fun, in a childish way, I guess playing on Settler, but not even my youngest testers would seriously consider a game at that level.