That "fair" histograph is mostly, actually, it IS all dependant on the SIZE of your empire and the SIZE of the cities, and the happiness of the inhabitants.
Commercial is so important to reduce corruption as it makes a large empire possible. The only exception is if you are playing on an island map.
If you have a decent road connection and just 10% of your money to luxury, you shouldn't have difficulty with angry people on regent, especially with your warriors "suppressing unhappiness"
If they still resist, you can make those temples with a rush, and it only costs 1 or 2 people. They get over it rather quickly, IMO.
Culture is more abundant in scientific buildings like libraries or universities. Literature is one of the first advances i get, so i can get the republic. I go for libraries first since i trade enough for luxuries.
If you are expansionist, you need commercial to reduce corruption in that big empire you are making.
The only nation with expansionist and commercial is the English. The Iroquois are not that good.
BTW a golden age can occur at any time, usually after u make a wonder that matches your civ's attributes. Are u only getting the ages in the ancient time?
Try to improve your skills after then, they might be lacking if u can't hit a golden age after the pyramids.
Commercial is very important on large maps. On a smaller map, the Iroquois might be ok with their UU in a fast game. But in large, complex games, you are better off with commercial.
