KJ,
1. David haMelech disagrees with you. When he ran away to Gatt he said that he was expelled from Hashem’s inheritance (Shmuel Alef 26:19). Chazal also disagree with you. The first mishna in Gittin gives the northern border as Acco. The former was because Gatt was not part of Shaul’s kingdom and the latter because it was the border of Jewish settlement. Rabbi Menachem Leibtag has an online analysis entitled Masei: The Borders of the Land of Israel/
2. The Golan is part of Ever haYarden. Eilat is near Etzion Geber, which was conquered by Shlomo haMelech and again by the IDF. Both were kibbushei rabbim.
3. It is not correct to call a state as the Land of ——. One does not, for example, call France the Land of the French. The term Medinat Yisrael was chosen to signify that the state belongs to all Jews.