Thanks. Yes, it is a shame about the midi, but hopefully I'll have a live performance soon.
As far as the composition goes, I wrote them in chronological order, so I'm not surprised that you liked the third movement best because I think it is the strongest of the three. But I'm certain there are themes in the piece - for example, the melody that the violin has at the beginning of the first movement (a few measures into it) permeates the whole movement. And the second movement is especially thematic right from the start. In fact, near the end of the third movement, the theme from the second movement returns to provide a connection from the listener.
But you're right that there is no one unifying theme that is in all three movements, but there aren't many quartets I can think of that do that. Usually, each movement has it's own themes and occasionally a theme from a previous movement may return. This is true for most other "traditional" forms (for example, Rachmaninoff's third concerto. Each movement has different themes, but the ideas from the first movement for example reappear in the other movements.)
As far as the piece being generic, I'm not exactly sure what you mean. It is a tonal piece for the most part, but I like to think it is a more personal tonal work (in other words, it would be hard to roman numeral analyze most of it). But keep in mind it is my first larger work so of course I'm sure I drew inspiration from other styles and other tonal languages.
I'm studying at the University of Tulsa, by the way. But thank you very much for your criticisms... it is nice and educational to hear constructive criticism.