more friend slots perhaps 175 (more than the new base line) additional party slots (again more than the base line)
Now this one is fully not up to me, but that being said, I do feel that it would be nice to allow you guys to have a few more slots. With that in mind, to balance it, it would almost be necessary to increase the other ranks as well (depending on where they sit now). Why I say this is because Obsidian already has 50 more slots than Emerald in friends, which is the biggest difference between rank upgrades by far (Iron: 20, Lapiz: 30, Gold: 40, Diamond: 50, Emerald: 75, Obsidian: 125). They also have 10 more slots in a party free then Emerald, which again is the biggest jump between rank upgrades (Iron: 4, Lapiz: 5, Gold: 6, Diamond: 8, Emerald: 10, Obsidian: 20)