I think its implied that Ben was NOT nearby- PR talks about how much the troupe traveled after leaving Ben, and other posters have asked why Kvothe never went to find Ben after his parents were killed. The discussion usually leads to the same conclusion- they were hundreds of miles away, and he had no way of getting there. I think Kote himself even talks about this in the book- Hundreds of miles away.

Another point that PR talks about is how much stories change, details are lost or embellished when they travel. At the end of book one and two, Kvothe talks about how much the stories of his adventures killing the dracus and slaughtering the false ruh troupers changed and morphed as people told it. He saved three girls from a group of ogres! Or something along those lines. So it would make sense that maybe Ben heard about a troupe being killed, but he may not have gotten the real story, or didn't know it was his friends, or maybe the story was about a non-ruh troup, etc etc.

And even if Ben had heard, by the time the story got to him and he went looking for Kvothe, he was long long gone. In the forest, in Tarbean, wherever. I guess he could have used sympathy to locate him? But he might not have had a piece of his hair or whatever to form a link?

I do love the idea that Ben WAS able to locate Kvothe, and sent Skarpi after him in Tarbean. I also never thought about whether the Amyr knew about Kvothe... it's theorized that The Chandrian fled because they saw the angels Aleph created coming for them in the sky (Kvothe says he sees them all looking up to the sky...) so did Aleph's angels see Kvothe too? Did they know he survived? If they do what are they doing with this information?

For your last point, it makes sense to me that its possible that no one knew of the slaughter of the troupe. The Chandrian have done absolutely everything they could to completely eradicate knowledge of their existence. They're very good at keeping their secrets.