I've been thinking about this, and how it could be simulated.
If crew worked somewhat similar to labour hours, in the sense you had a certain amount trickle in over an hourly period, this would make rum more vital while at the same time crewing at sea/open world also less of a exploit. Since really you should have to atleast dock up to re-crew your ships and rum should be the only alternative to repairing crew at sea & not just in battle.
When it comes to the mutiny aspect, i think if something was to be represented as such, it should not entirely be called mutiny, but more a focus on retention of crew instead. So higher wages for crew will lead to a higher trickle of crew over an hourly period to be recruitable then if you paid them a lower wage. So if you're taking a 1st rate into a patrol zone, killing alot of players but losing alot of crew, or you're a requin focused on boarding, but losing alot of crew to boarding in the process, your choice of replacing said crew will either be with huge stocks of rum at sea or paying more in wages to increase hourly trickle of crew to be obtained at port. Thus limiting ability to raid at sea unless carrying a good amount of said supplies or having to operate within range of a port which then perhaps begins to involve the realm v realm aspect on importance of ports. If wanting to get really draconian with such a mechanic, rum could be automatically consumed per day at sea aswell has being used to repair crew. Lack of rum while at sea will result in loss of crew to manpower pool (crew at port) or perhaps reduced abilities, e.g longer reload time, lower morale etc. This could allow for some more thoughtful play if trying to deter an enemy force from entering a port battle or blockading a capital port, attempting to run down their rum supplies at sea by standing each other off to make them return to port, and allow for logistic roles of ships carrying supplies if campaigning far from a home port.
Like any retention in a business, if you paid a low wage, and with employee turnover you may be operating at 500 employee per day, to simulate employee leaving and coming, if the wage increased, that business will improve their retention increasing the amount of employee they're retaining per day.
Overall, this should give new players a more cost effective & forgivable means of crewing many smaller ships and being able to lose them alongside said crew while also adding an extra cost to more experienced players in crew heavy dependent ships whom will have to take into account their crew numbers at sea, hull space for rum rations or ability to operate away from port without being able to obtain crew from their daily reserves if not dependent on rum.
If wanting to really focus on a mutiny aspect alongside retention, There can be 3 edicts that can issued weekly or daily, for example of the top of my head.
High Wages - Morale Normal - Retention of Crew (daily cap high)
Low Wages - Morale Normal - Retention of Crew (daily cap normal)
Floggings - Morale Low - Retention of Crew (daily cap high)
Could also make Crew supply & Labour hour supply one of the same thing giving it a correlation to give more focus on the above edicts.
Economy wise, think it will allow new players to get into the rum making business and be able to distribute to a wider spread of port.
Foreseeable problems or advantages depending on how percieved, or how it could affect player behavior, non-capturable free-ports will gain more emphasis has ports to raid behind enemy lines with