What was life like in historical international port cities (e.g. Nagasaki)?

by Exotopia

I'm engaging in a world-building project, and I'm wondering what daily life was like for the average resident of international port cities like Nagasaki up to and including the Meiji era? I'm using Nagasaki as an example, but any relatively cosmopolitan port city around the world before 1900 would work well too.

In particular:

Were there any types of characteristics that were conducive to the growth of bustling port cities/trading hubs? My basic research indicates that sheltered ports to protect ships was one common factor. Were there any others?
What types of social, economic, or governmental forces were the most influential?
What were relations like between trading merchants and local residents?
How were foreigners in these city kept "under control" e.g. ensuring that they obeyed local laws, did not stray from areas they were supposed to stay in?
What types of divides tended to afflict these cities? E.g. were there large socioeconomic divides between the rich and the poor?

Anything else that you think may be interesting to point out, or which people commonly misunderstand, would be really helpful as well.

Thank you in advance!

Hi there - we're happy to approve your question related to your world-building project, and we are happy for people to answer. However, we should warn you that many flairs have become reluctant to answer questions for such things, based on past experience: some have a tendency to try to pump historians for trivia while ignoring the bigger points they were making, while others have a tendency to argue with historians when the historical reality does not line up with what's needed for a particular scene or characterization. Please respect the answers of people who have generously given you their time, even if it's not always what you want to hear.

Additionally, as amazing as our flair panel is, we should also point out that /r/AskHistorians is not a professional historical consultation service. If you're asking a question here because you need vital research for a future commercial product such as a historical novel, you may be better off engaging a historical consultant at a fair hourly rate to answer these questions for you. We don't know what the going rate for consultancy work would be in your locality, but it may be worth looking into that if you have in-depth or highly plot-reliant questions for this project. Some /r/AskHistorians flairs could be receptive to working as a consultant in this way. However, if you wish for a flair here to do this work for you, you will need to organize this with them yourselves.