I understand what you say, but I think these contemporary techniques are just tools at hand, and I can use it freely. I didn't want (in fact I don't like it very much) to sound "aggresive" or similar. So, I wrote that way.
I know about transposition of instruments, but for writing, it's clearer (for me) in concert pitch.
The transpositions you mark on your clarinet are incorrect. Everything is in concert key.
I think the idea is clever, but the writing is much too safe, in terms of the rows. Orchestration-wise, some fast jumps would be a little bit maddening, but possible...
Klangfarbenmelodie is a technique Webern used a lot and I think a piece with that sort of theme in mind would really benefit from that. Combine that with "musical autonomy", where the first six notes of a row are transpositionally and inversionally equivalent, you would get a really self-referential and backwards sounding piece which could be cool.
It does sound good, but it felt like very clear, safe, Scelsi or Webern or something. From here, I think you can branch out more.
On the whole, pretty nice. Some of your chord markings were a little bit off, I think. For instance, when you have an F in the middle of an E-flat 7 chord, that's an E-flat∆9 chord or "add 2" depending on the register. I'd go back and fix some of those.
Some passing or appoggiaturas or some sort of non-harmonic tone was consistently wrong, and to be honest, I can't really pinpoint it. I can see one in the chorus where in the third measure of it you clash a B natural and a B-flat. I think the augmented 4th in the 5th measure caused by the D natural was weird too? Like I said, for some reason I can't find all of them. Maybe go back and look for non-harmonic tones too?
Other than tones, I think you got the feel of one pretty well... better than I did starting out with these. Nice!
Sometimes I also write very very short pieces just to try new sound comination, serial rows, etc...
I like the word oxymoron and its meaning:
made up of two or more words that seem to be opposite to each other, or actually are opposite.
For example, the words "Wise fool", "Warm freezer", "Legal murder"
In English the plural is oxymora (as other Greek words). But in Spanish the plural is not clear: oxímorones, oxímorons, ??
Well, these are serial mini pieces: I keep them as ideas for other things, or who knows, to make a set by themselves.
While the form is definitely that of a rondo, I see it as kind of a mix of that and a passacaglia, which is interesting, considering how often the main motif repeats. On it's own though, I would agree with Luis, provided that wasn't your intention. I feel like you don't necessarily travel with the harmonic structure that much when given the opportunity... simply a collection of 4-bar phrases.
It does sound very nice, though, and well orchestrated at that. Some of the left hand parts with Pedal might get a bit messy, but with control it should be fine. Well done.