Re: What are your favorite strategies for getting the most income possible per turn?
Your ideas are good ones. I also:
- Send an agent or admiral to make contact with other factions in the early campaign, so I can trade with them (especially when playing a Hellenic faction)
- Specialise provinces, for example constructing agriculture in grain provinces, to get as much benefit from bonuses as possible
- Multiply bonuses, for example Egypt starts with grain regions (bonuses to agricultural income) and can build the yellow grain market chain (more bonuses to agriculture income) and the sacred grove temple chain (even more agricultural bonuses)
- Try to expand towards an edge or (even better) a corner of the campaign map, so I have (relatively) safe provinces which are far from any enemy
- In safe provinces, convert most military buildings to money-making buildings (trade ports as well as the brown and yellow chain buildings you mentioned)
- Avoid appointing generals who increase corruption, and research technologies which decrease corruption
- Send rival party members on diplomatic missions (mainly to increase their party loyalty, but also because you sometimes get economic bonuses such as a generous tribute or even a gift of a settlement)