I use the +2gold from trade route card and I definetly use the -1gold per unit card all the time.
For the city states, I've 5 of them encounter in my game for now but none of them is a comercial city state.
I didn't see the card that gives +4gold per trade route yet. That would certainly help.
For my army size. It is not big not small I would say, just enough to keep my borders safe. I don't understank how the romans could keep an army as big as I have with only 3 cities (I took rome in a suprise war they declared on me when we were best friend). They got legions everywhere along my borders with 3 cheap cities. I play normal difficulty by the way.
I wanted a bit more troops to attack the romans and since there is only 2 niters on my continent and it is way down south inside the vikings territory soo i'm sticked with pikeman and cavalier (can't get rifflemans) and this is another problem but i read on other treads that this is normal.
One other thing, as I said in my first post, i do 3 to 5 gold per turn right now with every policy cards that could help and buildings, comercial hubs in every cities, internal trade routes everywhere.. and barely do 5 gold. And this is when not at war, because at war, it's -10 gold per turn automatically. Can't figure out all of it why but ammenities go down, people get mad etc etc. Anybody else strugling with money or it's just me?