Factions to encourage different types of player interaction

I've been trying to think of a way to encourage more cooperation between crews. I have no problem with the current PvP system - it adds an element of risk to the game - but at the moment there is no real incentive to work together and I'd like to see more variety of player interactions. One way of achieving this would be to create 3 or 4 different pirate factions that players could join in game. There would be a league table for which faction had collected the most gold, and it wouldn't differentiate between gold from voyages and gold from PvP, so it wouldn't incentivise one style of play over another. At the end of each week everyone in the faction on top of the table would get a reward and the tables would reset (gold collected by individual crews would still go to them in the same way - I don't see any need to overcomplicate that system or create systems that could be exploited). This would encourage players to help out or atleast ignore players in their own faction, particularly at skull forts etc., and give a better indication of who is likely to be hostile.

Each faction would have their own flag (or maybe just a colour/pattern on the wind flags so that ships can still have their own unique flags) and there would be unique faction cosmetics available. There could be faction noticeboards at outposts and NPC faction Admirals in the pirate legend area.

Players could choose to stay unaffiliated, and could also leave/change factions but there would be a cost and a cool down period involved in doing this. I don't see friendly fire being turned off for ships and crews in the same faction, but there should be some sort of penalty for attacking others in your group - perhaps a hefty fine? If you leave or are suspended from a faction you would still own their cosmetics, but they would be locked until you are reinstated or rejoin.

Having a limited number of premade factions rather than player-made ones would allow the servers to create a balance between the different factions and neutral players to keep things balanced. I also don't think there should be a way of finding other ships in your faction except by stumbling across them like any other ship - that way it wouldn't be easy to create big unstoppable fleets. Premade factions also makes it easier for Rare to create cosmetics which cater to them.

What do you think?