I know economics is necessary and I'm actually amazed at the fairly good implementation here.

I was being a bit sarcastic about the economics part but economics class could be more fun if we talked about opportunity costs and round about production in terms of Total War in say whether we should rush to ships as they provide better long term returns, etc.

I also don't sink them until I'm fairly set up and consider the economic consequences.

I like to have all the islands that I can get as naval bases and is acutely aware of sharp cost of ship upkeep and thus have at most two ships in each sea lane before deep water ships or less after that with deep sea ships ensuring trade lanes don't get cut because of a storm.

This is different if I'm in a naval war though. I would frequently premptively start a naval war and wipe their entire fleet off the map within a year, launch amphibious raids to destroy their sea facilities the next, get my troops back if possible, pull out my ships for autocease fire and then go back.

I can often reduce a glorious enemy navy to shambles and risk little trade loss.

This also means that they don't get benefit of large trade networks and keeps them weak.

If I feel like having a challenge, then I don't touch their navies and wait for them to backstab me.

also, it's nice to work with agents and try to kill off their faction. they get big armies after reemergence but their oversized fleets are gone.