Names:  He's introduced as Beor because this is written from the POV of the Noldor, and that's how they think of him.  "Rebirth" is a lofty concept... I'm mindful of the fact that a lot of Asian immigrants here in LA adopt English first names to avoid the awkwardness of having to teach folks how to pronounce their real ones.  Of course, Balan doesn't strike us as unpronouncable, but Beor might just have seemed more comfortable to the Noldor.

The people of Caranthir:  Agree with the folks saying that the 3C's are arrogant beyond belief.

Edain and the green elves:  I think the different reactions may have been due to the way the Edain presented themselves.  If the Haladin were few in number and timid, they could have been easily intimidated by the green elves.  But the people of Marach "were a tall and warlike folk, marching in ordered companies," which creates a very different impression!

Going West:  Well, we know the Noldor can't, because of the curse.  And the Sindar appear to have no interest.  So I don't really see anyone really promoting that idea to the Edain, whether it would be possible or not.  My guess is the Edain were interested in the west of Middle Earth, which seems more fertile and safer.

The elves attitude toward the Edain: I really like Menelwyn's thoughts on this.  But until this point, I was getting the uncomfortable feeling that the elves thought of them as cute, furry creatures on two legs who might be useful.  To answer Luthien Rising's issue about why it seemed natural for the men to be vassals of the elves, I think the practical answer is in the short lives of men vs. the immortality of the elves.  It's natural for someone of, say, age 30 to feel subordinate to someone ~1,000 years old!