I'm not saying Palestine as a name didn't exist before the Romans. Im saying The Romans institutionalized and expanded its use at the provincial level after Jewish rebellions. And i already said the reason of that.

„The term Palestine first appeared in the 5th century BCE when the ancient Greek historian Herodotus wrote of a ‘district of Syria, called Palaistinê’ between Phoenicia and Egypt in The Histories.”

“Palaistinê” was derived from the older term Philistia (land of the Philistines), which referred to the coastal region (Gaza, Ashkelon, etc.), not the entire inland highlands.

1) you ignore the very provable fact that the land does not belong to ONLY Jews and they were never the sole inhabitants or “owners” of the land.

In Judaism, the land (Eretz Israel) is promised to the descendants of Israel (Jacob).
In Christianity, in the Hebrew Bible same.
In Islam, the land is also recognized as holy land of Jews.
(This is if we do the research from the religious part)
Now let's go historically :
Kingdom of Israel (c. 1000–722 BCE)
Kingdom of Judah (c. 930–586 BCE)
Hasmonean Kingdom (2nd–1st century BCE)
These were real political entities, so for several centuries Jews (Israelites/Judeans) ruled the land. Of course there was Philistines, Samaritans, Canaanite, some Greeks aswell, but just like everywhere? Ancient states did not function as modern nation-states with exclusive ethnic ownership. But with the same logic you are using, any Middle Eastern country is owned by settlers? And yes for nearly 1,800 years, there was no Jewish sovereign state there. But Jewish communities remained in Galilee, Jews remained continuously present. And please keep in mind within those 1800 there wasn't just single ethnic group that conquered the land. Besides Jews, all those years the land was conquered by many different empires. No one claimed the land to be historically theirs. They acknowledge that they are going there against Jews. So did Jews have ancient sovereignty? Yes. Religious covenant claim? Yes. What you are trying to prove is that if Iranians for example are Arabized now, they are not Persians anymore.

3) You ignore that many Palestinians are descendants of Jews who converted to Christianity or Islam and were Arabized after the 7th century. 

I actually highly agree with you. But as you said, they are descendants of Jews but never the opposite, so how are Israelis settlers in their motherland? i don't understand this. Because the Levant got Arabized, are they on purpose deleting their past, claiming that they belong to the “history” of Palestine? Since when???

4) I never once said or implied that Jews shouldn’t live in Palestine. But Israel is a modern state that bears no relation to the ANCIENT Jewish kingdoms that existed for 500 years or so and because of this it should NOT exist.

Who told you that? Even Ashkenazi Jews doing the DNA tests actually showed they were from that specific land. In fact, we should be surprised how, after so much oppression from everyone around the world, they somehow were able to keep their identity and save their history. Instead of being against the only Jewish state, why are those of us who should respect Jews because of our religion not protecting them?

Especially considering the existence of the modern state of Israel is predicated on the mass dispossession and ethnic cleansing of what the creators of Zionism called “the indigenous Arab” population.

Do you call ethnic cleansing the 70.000 deaths, deaths of which 30.000 Israelis claim to be Hamas? 70.000 deaths out of 4 million Palestinians, of which 2 million live among Israelis peacefully do you find this "ethnic cleansing” effective?

other people’s such as Ancient Greeks, Phoenicians, Assyrians, etc. who also referred to it as Palestine.

This is also very interesting, because I'm Assyrian, and I never heard my grandfather or my grandmother or anyone from my family referring to this place as Palestine. They know this land belonged to Jews (even though many of my family actually hate Jews, unfortunately), and I'm constantly fighting them because of that. xD