Do you know of Poulenc? He's my unhealthy obsession and also a 20th-century French composer. I can really hear the modern French influence with the obvious melodic weaving and the delightful harmonies that flow effortlessly but are occasionally awry (03:52 is a good one) Your adhesion to a strict stucture helps make the multi-tonality make sense too. I also totally get the pain that comes from plucking out articulation so that things sound more natural. It's a headache to go through, but it's polish that definitely helps this piece shine. I mean, the mixing you did doesn't present any problems to me. I'm refreshed by this improvisatory wandering and thank you for doing this honestly.
You should be fine with the harpsichord in the context of the contest. I would hope the last thing it'd be considered is a string instrument.