Welcome to Young Composers! You've definitely made a splash with your first entry here. I enjoyed listening to it. It's good to hear somebody who is able to pull together many of Brahm's key traits, and manage at the same time not to sound like a Brahms clone. I commend you on a lovely accomplishment with this Piano Trio.
First off, if I am not mistken, the 'harp' that was used was meant to simulate plucked strings because you couldn't change tracks? That's the sort of things I have done in my works. It does work pretty well, and I thought using plucked strings in places definitely added to this work.
There are a few areas where I think you can improve this work. The opening introduction doe snot prepare the listener for the material that is coming later. Until we reach measure 21 at 0:50 we really don't even get a taste of the material that is to dominate your work. I would like to state that I love the section from 0:50 to 0:57. You can almost hear the music wanting to land on the fifth ala Paganini. Of course, I prefer what you did.
Still, the rest of the introduction is very weak and does not emotionally prepare us for what you have in mind. If this is to be a one movement work, you might want to contrast the opening with the ending. Consider Dohnanyi's Second Piano Quintet. The opening of the first movement mirrors the close of the work. Given your extensive and atmospheric coda (which I adored), you might want to think about that.
One section that sounds strange to me begins at measure 86. The runs in the right hand of th epiano sound a bit disjointed. I cannot hear the change of chords that I think you are trying to emulate. Instead of using duples of notes, perhaps you should use four notes in a run. That might sound better, and certainly more Brahmsian.
Some of your transitions are a bit too sudden. For instance, the transition from a fast paced beat to the slow rhythm at measure 129 happens without any warning. Sometimes this can work, but it didn't for me here. Even the second time you did it I was surprised. It sounds disjointed, and I think you can ease into that section a little more gracefully.
Now, you do hav ea lot of really great transitiosn too. for instance, the section beginning at measure 244 is maserful. I was on the edge of my seat with excitement as you propelled us forward with rhythmic intensity. Your use of piano and strings would have pleased Brahms I am sure!
I rather liked your fughetta, I dont't hink it needed much work.
Your coda was the most Brahmsian part of your work I feel. The use of off tied eighth notes in the bass was excellent. I commend it and recall seeing it often in Brahms work.
I am impressed with your trio, and think it is quite well done. There are just a few weak spots that I thnk you can really improve on.
Good luck with the work!