Ruggiero Ricci — American Musician born on July 24, 1918,

Ruggiero Ricci was an American violinist known for performances and recordings of the works of Paganini... (wikipedia)

Every violinist has a different style, so it's important to be able to recognise their styles. You don't have to like everyone's style but you have to know these styles.
When you can hear a violinist, that is better than you, then you learn from him, because if you play with somebody who is worse than you, then you go down.
Well, rhythm is 90 percent of the interpretation.
Of course the most difficult thing on the violin is always intonation. The second one is rhythm. If you play in tune, in time with a good sound that's already high level. Those three are the main things.
A good interpreter can take a piece of bad music and make it sound pretty decent, while a bad interpreter can take good music and make it sound cheap. I can tell that some people have a bad taste, and unlike on the piano, they smear around a lot, that is bad taste.