I like this work.
I can't give you a deep analyse of the piece, but I think I would let the guitar play the minore chord in the second repetition of the second frase. I think in meassure 11, difficult to say, since you not posted the score. I would keep the melody equal, but just use the minore chord in the second repetition. Later in the piece (at the same melodic frase), you will also need to sink the clarinet a semitone.
But as said, I liked it! Some fine contrapuncts (is it counterpoint in english?), and I simply love counterpoints...