Thanks, @PeterthePapercomPoser. I browse through the forum from time to time, although I do not have much time to listen lots of things attentively :S. I have bookmarked some of your "20th century harmony" exercises because I am interested in trying to study that book and I loved some of the ones you made. Will probably comment on some of those when I have a little time to analyze the scores! (and probably use them as examples to compose my own exercises!)
Somehow I feel it is too short and that it stars too abruptly so I was thinking about options to extend it. You pointing out about the "double exposition" made me realize that, what I currently have, might be understood as two different themes (or parts of a theme) starting in m.1 and in m.7.
I might play around with some different forms but I was thinking on extending those ideas into full themes and then playing them like this:
A section
1. Theme I in Cmin
2. Theme II in Gmaj (or minor)
B section (The section I have composed).
1. Theme I in Cmaj with sudden transition to Theme II in Cmin and coda.
I am not sure if it would be a valid form or not, I guess it would be like a binary piece based on the exposition + recapitulation of a sonata form.
Maybe I end up failing and just adding a final chord to what I have now. But I will give it a try.
Thanks for the feedback!