I am sixteen years old, and I big fan of your works, especially the Song of Ice and Fire series. I have a few questions to ask you about the series, if you'd be kind enough to answer them...
1) Is the series based in any way on the events leding up to the Battle of Hastings? Various themes (different leaders vying for a throne, the appearance of a comet in the sky, bastards becoming great leaders) seem to be echoed in your story.
I did not have Hastings in mind especially, but I suppose there might have been some subconscious influence. The comet was actually more drawn from the Bard's in JULIUS CAESAR, as well as the ones actually in the sky as I was writing.
2) Where exactly are the cities of Yi Ti and Asshai in relation to Qarth? Are they on the same continent, or across the Jade Sea?
Yi Ti is to the south east of Qarth, generally, across the Jade Sea.
3) What are the approximate populations of King's Landing, Qarth, Asshai and the Port of Ibben?
Populations were largely a matter of guesswork in such times.
4) What exactly are the Shadow Lands? Do any significant civilizations exist there, or are they simply a barren waste?
Keep reading.
5) About the two men Arya saw conspiring to restore Dany to Westeros in GoT--one is obviously Illyiro, but who is this other? My friend seems insistent that you confirmed that it is Varys, but IIRC, Varys is hairless while the man Arya saw had a beard.
Varys was a former mummer.
Could you clear this up, or will we find out later?
It was Varys.
6) Where exactly to the Jogos Nhai live? On he eastern coninent, the continent to the south, or across the Jade Sea? Are they from such cities like Kayakayanaya that you mentioned in GoT?
There will be more maps in future books, but there always need to be mysteries beyond the hill as well...