First scenario. You have 6+ friends who want to play Sea of Thieves. From the launch menu, you could invite them all and sub-divide them onto different ships. For example 2 x 4 or 3 x 3, or even 3 sloops.
Second scenario. PvE mode. There is a specific PvP mode but what if a PvE mode. 8 players max and it would be sort of similar to the Forts however new features could exist only in this mode. Players would fight through countless waves of skeletons and maybe even flying ghost ships where to defeat, you would need to climb into the towers and fire upon them with cannons. This mode could also work like some of the tall tales where you need to check maps or go through riddles to complete tasks. The rewards could be maybe less than a fort as you wouldnt have the risk of people coming in and stealing loot.
Third scenario. Alliance board in the taverns. You would be able to recruit people and put in conditions and objectives into the alliance. For example; Ranking up Merchant - experienced players only - cannot leave alliance unless leave game.
The end part is something which i think may be somewhat controversial in this community however this third feature i feel is more to bring people together and would be more of a way to ensure others dont leave and steal all the loot.
Lastly, as a note. I want this thread to be more of a way to just suggest features and discuss in a friendly way.