Jade Yes, it's the Latin translation of a Greek/Hellentic version of either a the Hebrew or a Hebrew Arabic name which would be Joshua in English. Either the Hebrew or Hebrew-Aramaic names would have been common during the time period.
MHD The post-Gospel NT writers often took Judaic writings to mean things to support their claims that Christianity had usurped Judaism and were looking for evidence, however, the Gospel writers often show that the Jewish population he was around had no concept of the idea that the Messiah was meant to suffer and die for them, and would even denounce the concept to his face when he told them he was going to do so. Those people were eager for the Messiah (there were dozens upon dozens of people claiming that they would become the Messiah or had others do so at the time - claiming to be the one who would become the Messiah wasn't a crime and isn't a crime, as it was and is believed that one or many in each generation have the potential -- it's fulfilling it that's been the problem) and they knew that the Torah prophecies for the Messiah are quite clear on what a person had to do to be the Messiah, and none of them have to do with suffering or dying through suffering before the prophecies are completed.
The identity of the servant is established repeatedly in Isaiah 41 :8-9; 44:1-2, 21; 45:4; 48:20; and 49:3. They all repeatedly say that Jacob/Israel is the servant. The narrator of section 53 is specified in chapter 52 as the nations of the world who are startled at that Israel, who is often referred to as the "servant of the Lord" (The Messiah is never referred to as such), coming through such a numerous states of sorrow into a brighter future. There are many passages on the Messiah, but this isn't one of them, and can only be taken as one if you don't read the rest of the book.
Josephus was a Jewish man who was paid by the Romans to write these things (after they captured him and they pretty much owned his life due to the way he was captured), and many of the things he wrote have been proven to be false in order to make the Romans look better. He's pretty much only a source if you can collaborate it with someone else. He also wrote very little about Jesus, and what he did was negative (more negative towards his family). And 20-60 years is a significant time when looking for first hand accounts, because it means they are unlikely first hand accounts and those that are are marred by issues of memories, particularly in a time period with comparably short life spans. Mythos take over in much shorter time spans - just look at the crazy things written about Roman Emperors very shortly after their deaths to see how fast mythos about a person can spread.