I very much enjoyed this. What else have you written so far? I'd certainly encourage you to keep on composing.
On the idea of using a tone-row in a tonal way: are you familiar with the Shostakovich violin sonata?
Some first impressions--these comments are based on listening once through the whole piece, resisting the temptation to rewind, trying to experience it as if in a live performance (although I jotted down some notes as I went):
First of all, I have to tell you that at about 2:30 in, I almost stopped listening. I'm glad I didn't. It seemed that you planned to use the silences as a structural element throughout the piece. Conceptually it's a neat idea, but the effect came across to me as painfully disjointed; at some point you need something that simply sweeps the listener along. The necessary sense of flow arrived just in time, just before 3:00.
Viewing the piece as a whole, I like the range of textures you get out of the piano, a good variety of articulation, pedalling, different registers and so on. However, you should recall the story of the boy who cried wolf: if you try to use every register in every variation, it loses its power. At times I think you can be more restrained (a couple of specific suggestions below).
Generally I think there are too many "mezzo" dynamics: I'm hearing lots of mp and mf, where I'd rather have a whispered pp or a full-bodied forte. Of course this may not be the composer's fault (I haven't seen the score), it's possible that the performer is to blame here
Between about 7:00 and 8:00 I felt that it was a bit "waffly". The fugato section at 8:10 was a nice contrast, but I thought it could have been even brighter (maybe faster?)
At 9:30 you almost
created a spine-tingling sense of menace. This is where you pay for "crying wolf" earlier: imagine how much more powerful the rumbling start to this variation could have been if we hadn't heard so many low bass notes earlier. (In fact I wondered if this could have been an octave lower.)
The ending of the variation at 11:25 felt too abrupt, I didn't quite follow the logic here (although this could be my own failure to take something in on on a first hearing; it's possible that it will make more sense next time I listen). The start of the next variation I thought could have been more spooky (maybe play it slower?)
The passage between 12:30 and 13:00 was for my taste the most effective part of the work: the juxtaposition of the bare fifth with something much more complicated almost out of sight over the horizon created a very intense atmosphere. But then between 13:00 and 14:00 it seemed to be going round in circles: my attention wandered a bit here.
The chorale emerging from the shadows at 14:15 was also a beautiful effect (shades of Ives here?). I wonder how the passage between 14:50 and 15:20 would sound if there were no low bass notes at all, aiming for an ethereal or disembodied effect (half a minute without crying wolf!)
It felt a little as though you weren't sure how to end the piece--it seemed that it was working towards something dramatic, some sort of frenzied explosion perhaps, but then it stopped cryptically and suddenly. (Then again, you're not the only composer to ever do that, and it's entirely possible that your taste in such matters is better than mine.)
The general impression is that you have a lot of good ideas, and created some powerful moments, but at times you're putting in more than you need to. Sometimes less is more. But overall it's fascinating and satisfying to listen to. I hope you find my comments constructive, or at least interesting.
I'd quite like to see a score of this, also anything else you've written.