Cool list, it is interesting to see what a foreigner doesn't quite understand.
Sofia University - don't even bother trying to figure it out. I've been there a few times - it's impossible. Even the people that go there take a year to figure it out. I personally think they should have maps all over the place with "where you are" dots on them.
Now, banitsa you can find in the States. In all the big cities, NY, Chicago, where there's greek population. Go to any greek bakery - the one with feta cheese and spinach is called spinakopita, and the plain one just with cheese is - cheese pie. They are delicious, often made with real cheese (to let you in a little secret, in Bulgaria more often then not they are made with "izvara" - a yogurt based cheese, close to ricotta)
Good luck extending your stay.