peace
First, I just want to say that pride and nationalism ARE NOT sins in Islam. Kibr (I don't know the English word for it, sorry), which is thinking that your better than other people for purely selfish reasons, such as wealth, and thinking that your better than someone just because your, for example, wealthier. However, this does not mean you cant love your wealth. This is a major
Second, As for sin the Al-Aqsa mosque, you should now that it is under Muslim authority, the Israelis granted Muslims that.
Third, cant you love your country AND ISLAM? me myself, i love my religion, Islam, my country, KSA (although im against some government policies)
I also love my race and language, Arabs and Arabic, but this does not mean i don't love Islam, it just means i love my race and language, also this does not mean i think myself better simply because im an Arab.
and whats wrong about our beautiful flags.
Also, i don't think you should call any country a "kafir" country unless they persecute muslims for their religion. And some muslims are from, so-called, "kafir" countries, secular=/=kafir, a secular countries could have islamic laws, such as death for murder.
I hoped my answer helped
Peace