I'm not creating any sort of doctrine. If I were arguing something along the lines of "these passages show that Christians ought to be nationalists," then you'd have a point. That is not what I'm arguing, though. I am arguing that nationalism is not precluded by Christianity. There is nothing contradictory about someone being both a Christian and a nationalist. (Not to be confused with the talk about "Christian nationalism" that's currently in the media.) I'd hardly call that a doctrine. As for you, you have created a doctrine. Namely, you are arguing that Christianity is incompatible with nationalism. And yet we see here in scriptures that (a) God is involved in the existence of nations, (b) it is appropriate for us to have a special interest in our own people, and (c) it is our duty to care for our own families. Nationalism in its most broad form is merely (d) the interest in preserving one's own nation (which God has established), (e) a special concern for one's own people, and (f) a special concern for one's own family. How, then, is that incompatible with what's found in the Bible?
I wouldn't consider nationalism a form of "loving the world" such that one who engages in it cannot be part of the Kingdom. Does loving one's family mean that one is loving the world? Does loving one's dog mean that one is loving the world? Does loving one's vocation mean that one is loving the world? Does loving these things preclude one from being part of the Kingdom? I suppose some may argue that, but I believe it's without warrant.
In Acts 17:26, yes, Paul is talking about earthly nations. You haven't provided an alternative explanation. What else would Paul be talking about? From one blood (Adam) came all nations. God determined their existence and set their boundaries. These are earthly nations. What else would they be?
I have not disputed that faith is the sole pathway to being saved. Paul knew that, of course. That's why he was so distraught by the lack of faith in his fellow Jews. He desperately wanted them to have faith in Christ. If that's an "earthly desire," then take it up with Paul. He expressed it quite plainly.