it's a bit of a balancing act.
i don't actually manufacture every thing i need, for instance i have no tool shops, rope factories, cannon foundries, glass smelters, forest glassworks, war machine factories, weapons factories, provision houses. instead i bung them on my shopping list in various whare houses & buy them from the neutral powers that way. which rapidly earns you honour & builds up your standing, which unlocks attainments far quicker than running your backside off doing quests.
i have 3 population centres, 2 are restricted ascension rights, low demand/high taxation centres, there my "meat & taters " islands that generate a good flow of cash, & they pretty much run themselves. the 3rd is my high maintanence Nobleman island, & it takes a whopping 25 trade routes to satisfy the 12,000 to 13,000 Nobleman on that island. on the plus side, if you can bring it off they bring in a huge amount of taxation.
on the minus side, they will riot at the drop of a hat if there demands are not kept satisfied.