I would like to propose that an area maybe called "Bygone Allies" or "Lost Allies" or something like that be added to the character sheet.
1. Each player would be given initially 5 slots. Any ally that has been gone from the game 6 months or more would automatically be moved to the area. Additional slots could be purchases just as we can purchase additional allies and enemies now.
2. I do not know about everyone but once I have added a friend as an ally (or enemy), I am very hesitant to remove them, in fact I have have never dropped an ally (or enemy, except to move them to ally).
3. To me the game is primarily social. Hunted Cows you might not like this, but the game its self is incredibly boring. But the social aspects are probably about as high as any game I have ever seen. The game at least for me is secondary to the chat. I think that might be true for a lot of the players. The primary people we talk to are guild members, allies, and enemies. When the guild chat is light and all you see are dark purple dots in the allies and enemies it starts getting depressing. The game gets lonesome and the ties to it start unraveling until one day you just stop returning. It is not so much intending to leave for good as you forget about the game or just no reason to come back. This is probably worst for players with lots of stamina as it takes in some players cases over a month to recharge stamina. I actually stopped purchasing increased max stamina because it was over a week to recharge.
4. By adding the new area we can continue to honor our friends by letting them know if they ever rejoin that they were not forgotten and indeed thought about, but we can also see when looking for who all we might be wanting to talk to, see an area rich in people that are still active and might even be green dots.
5. Another idea might be to set up private chat areas, sort of like guild chat but player defined. You could charge FSP to initially create an area with 3 people limit at a time and charge to increase that size too.