I feel as though the lack of a colony option with the increases of city penalties in BNW is imbalanced. I think the game could benefit greatly from providing a secondary option when you decide to found a new city.
With the discovery of printing press you would unlock a new kind of unit called the colonist. It would be cheaper than a settler but more than a worker, and would require growth to be diverted to production like a settler.
Founding a colony would have one major requirement to fits its primary strategic function; colonies would have to be founded with a luxury or strategic resource in the immediate vicinity of the city.
A founded colony would decide based on what resource it had in its vicinity what type of colony it would become. The mechanics of the colony would be very similar to the city state in terms of how we interact as civs, but the major difference would be that the founder starts with a massive influence advantage, and a very slight bonus to the rate at which influence is lost. Instantly it would serve to provide your civ with a resource, and on top of that it would function like a city state and provide a specific small bonus. The size of that bonus would not be dependent on the era your civ is in, like city states, but rather on the population of the colony.
What type of colony you found would be determined by the resource you found the colony next to. Next to wine, spices or incense, it would be religious. Next to copper or ivory or any strategic resources would create a military colony. Next to marble, dyes, cotton, or silk would create a cultural colony. Next to whales, crabs, pearls, citrus or salt would create a seafaring colony. Lastly would be the mercantile colony which would produce special luxuries unavailable to mercantile city states. If founded near gold gems or silver it would simply make jewelry, and mercantile colonies will never produce porcelain. However if they are near furs they will produce coats, and if they are near sugar they will produce rum.
Overall I think this would balance the game, and allow for more expansion in the mid game. With the introduction of trade routes in BNW controlling resources has become a very important part of the game, and I think it would be interesting to have this new tool for controlling resources far away from your capital.