One think that I have noticed in my study of the Bible in different languages, is many names weren't "translated" but rather "evolved". I will give the example of Jesus himself, because the story is widely told. In Aramaic, his name would have probably been pronounced/written "Ehsuh" or "Eshu". Jesus and the Apostles most likely personally spoke Galilean Aramaic, but were preaching through Judah so they also spoke Hebrew. This was spoken in Hebrew as "Yeshua", or possibly "Yehoshua". This was then translated into greek as "Iesous" and into English as "Jesus". If translated directly into English, than the name would be "Joshua". (It would be a lot of hard work trying to get over 1 Billion people so start saying Joshua or their equivalent to it). I heard a pretty good explanation specifically for Jesus that both in the Greek and Latin languages that the "Sh" sound that exists in both English and Hebrew doesn't not exist. So when read it was simply pronounced as Yesua which in Greek was changed to Iesus/Iesous (The letter J didn't really pop up until 1524 and didn't find common use for much longer).
A second important point is that Hebrew has/was around for a lot longer than the New Testament. Lots of Hebrew names already had equivalents in Greek or Latin, and therefore those names were used. For example, Yohanan in Hebrew was written in it's greek eqivalent Ioannen, then John in English. It wasn't till around the 1500's when bibles were printed in English, and even then it wasn't until 1611 when the King James Version (arguably most famous) was translated directly from the original texts rather than other European translations.
The Bible, however, is debated in terms of WHEN it was written. It is generally accepted that the majority of it was not written by the figures that the books claim to be written by. For example, the gospel of Mark probably written wasn't written by Mark (rather, disciples of Mark or their disciples).
I would also like to point out something in your question that I am tripping over. You ask about "local readers". Most consumers of the Bible didn't even see it, they were read it by Priests, Bishops, Deacons, and Vicars. This brings up the issue of when the majority of common people were literate. This would have definitely been after the invention of moveable type, and accessible books. In the case of a primarily Catholic Europe, mass was held in Latin, and was until the 1900's when it became a debate wether or not the laypeople should understand what the priests were saying.
So, in short, the names fall into three categories. A romanization of a Hebrew name (Example, Methuselah), a name that already had a language equivalent (Like John, Mark, Etc), or completely new inventions in the case of Jesus/Yehoshua.
(Hope I answered well on my first comment!)
Reposting from the deleted thread:
A reader of Hebrew approaches that most famous ANE text, the Bible with different eyes for several reasons, but one of the most striking to novice readers is the deep significance of names to the story. The primary benefit of this is to realize how often storytelling in the Bible explicitly or implicitly relies on the meaning of names.
"Adam" is a common Hebrew word for "human" (not "man" in the sense of a male human). The actual Genesis 2-3 narrative starts off by calling him "the human," switching to later referring to him by name (by dropping the article). In translation, this is an awkward switch from "the human" (or "the man") to "Adam." But the idea is clearer if you simply do as the Hebrew does, and switch from "the human did __" to "Human did _," treating it as a proper name.
It's my opinion that you're better served reading the Bible in English with names translated out... saying that God wrestles with Jacob then gives him the name "Israel" doesn't mean much to the English-speaking audience--but saying that God changed the name of "Underhanded-Attacker" to "God-Wrestler" says quite a bit about what is going on in that story.
(As a side note, I also think translating out the names Native American style is helpful for modern readers partly because of what it means to them. The ancient Hebrews were inland people constantly struggling to protect themselves from wealthy, warlike, technologically advanced, numerically superior invaders. They were a colonized people struggling to maintain their sense of self against their colonial oppressors. The American Indian analogy is apt in many ways.)
Then there are really interesting/tough cases like Moses. Moses' name is given a Hebrew etymology in the text: "drawn out [of water]." But it's not a Hebrew name, but rather part of an Egyptian name. Moses means "Born-of-" and is usually found in names claiming patronage of one of the various Egyptian gods: "Born-of-Ra" (Ramses), "Born of Thoth" (Thutmose), "Born of Ka/Bull" (Komose), or "Born of Iah/Moon" Ahmose. Either name helps understand the story... Moses is repeatedly drawn out, especially from water. Futhermore, his name (and Miriam's too) indicate a rejection of his old world. The name of some God has been deliberately lopped off from it, and this is no accident.
(With all this said, apologies for the simplifications and linguistic slight-of-hand in this post... translating names intelligibly is a tricky business!)