The problem with many of those is that they can fall into the category of "Story-breaking". For example, we all KNOW that Calmemnon is going to come back in some horrifying way from Dar Zhan Vor, and to have some of his Legionnaires come back would be 1) telling of what happened, 2) kind of hamstrings PCI for telling that story somewhat. The same for the Khitani: Until PCI writes up the new Codex Arcanis or a Khitani Empire supplement similar to this Blessed Lands one, playing a Khitani would be a bit hard as we really no nothing about them and it crimps stories to reveal.
Possible options that are less-Story breaking:
1) Exiles from a 'proscribed' nation - From Canceri or Abessios are the easiest, and you can have certed permission to play an Exile/Expatriot from those nations, or even a simple "you can play an Ashen Hide!" While I'd love to see one from Ymandragore, I think that it is a bit hard to fit into the Living Campaign as any exile from Ymandragore would probably be hunted so much that they'd have to have a set of stat-blocks to give to every Chronicler at every mod they play for a 'random encounter.' Similar thing to the Malfelans, though it would be EVERYONE hunting you and not just the Ymandrakes.
2) Ability to play a Hainese/Legion of Unyielding Courage - We already have an option for playing a Bastionite val'Vasik, so possibilities for opening up the other two main 'free' nations of the Blessed Lands.
3) More "Descendant of" Certs - Allow players to be minor children or cousins (in character) of members of some of the ruling houses of Arcanis. Not one of Scipio's or Gerhardt's kids, but say a cadet branch of the val'Dellenov of Sylvania or the val'Ossan of Salantis, or even one of the Vassal families (like a Gracchi of Grand Coryan).
4) Minor Artifact - Allow the Heroes the opportunity to purchase a single published item of their tier or less that would otherwise not be allowed to buy (ie: Magical items which are thus far un-purchasable).
5) Portrait of a Character - Have yourself (or, with description, your character) done up by Pat Loboyko (since you're paying extra, you are basically using PCI as a broker for a commissioned piece). This could take the form of a Digital portrait, with extra money going to providing a REAL portrait (digital, however, can be printed. . .).
6) Cert Shirt Return! - I'd love to see more of these, and get some
7) A less-important 'special mission', say at a BI or Convention - Basically, you pay for the right to go on one of the special missions that were so famous about some of the earlier BI's, such as a commando raid on an Altheran Airship, while everyone else is defending the walls of a city. This is not a unique adventure where you learn terrifying secrets of Arcanis, but it is still a fun activity!
8) Knighthoods - Get a chance to play a former Knight of the Dolphin Guard, or Red Dragoon from the Western Lands.
9) Able to play a Descendant of Caneturec the Infernal, and therefore gain the ability to play a Psionic Dark-kin.