I am left-handed but it never was even brought up that I might play left handed. My father was my first teacher, and he was a violinist in the NY Philharmonic. But it never occurred to him either. I don't think it has hampered me, but I don't know for sure. None of my teachers ever even mentioned it. I remember reading old method books which said to switch the strings around, and play left-handed,but I have never seen it done. There is a picture of Charlie Chaplin playing a violin left handed. He and Heifetz seemed to know each other, and Heifetz tried the violin that way, and couldn't play it at all. It least that is what I remember reading. I guess anyone, even Heifetz, would have to relearn how to play if they suddenly switched from right hand to left hand playing.