How about making one or more of these new ranks play-time obtainable only, to distinguish the players who have really put the time and effort into the community?  For example, a player who donates for captain would only inherit the 100-day rank if they’ve actually played for 100 days, and it would not be available via permanent donation.

I’m not suggesting this should be the model for all of the new ranks, but there comes a point where it is not really fair to compare the value of a $10-perma-donation to the immense individual impact that Cysteen, lazydog11 or any of the other top-playtime folks have had over the years on player-retention by helping to foster a wonderful in-game community 🙂

That said, I like the progression of 20, 45, 100.  It feels smoother than the current transition from gunner to boatswain.  I think each new rank will feel challenging, yet still within grasp of the previous.