Nova: my likey. So slimy and rotten -- Tarkan will certainly add something to the game. I imagine, given your description of him however, that Faroz is not terribly fond of this half-brother. Still, filial duty is important to the King. . .
Bethberry: now why do you want to go and give a poor old GO like me a headache?
But to address your query.
Everyone in the game has a lot of latitude in creating secondary characters -- we will have to since, as you point out, this is an 'aristocratic' game and we will need servants, soldiers, attendants etc etc etc. All I ask is that everyone try to keep it from getting out of hand. I am not terribly fond of the idea of introducing player-characters for Alanzia. I have played in a couple games with different 'groups' or 'plots' and while they were interesting there were problems with co-ordinating them; some plots would go sterile waiting for others to catch up. I really do want to keep the game focused on Pashtia.
There are also some plot points coming along that might make Alanzian player-characters a bit problematic. . . (first hint)
All that having been said -- if an approved gamer wants to introduce a cameo character for brief time, and have that character written by someone else, then I suppose I won't have a problem with that. Obviously, I would want to be in on the decision however!