To be honest I did not really listen to all of it. But I like the last movement. It's pretty different from the first and second in a way that it started with G major then ends in C minor! but maybe it would be better if it ends in C major (but it's your work, so you have your own ideas).
But yes, there are some awkwardness in the piano writing at some places. And I think the strings writing can be slightly more adventurous. And the harmony in the first movement, sounds a bit pop-ish.
What is happening at bar 14? In the second movement? Nice piano entry btw. Nice cello melody and writing at bar 37. And nice surprise too at bar 52.
Btw I think you like to write in the style of a hymn. Because you have hymns all over this quartet. I think it's cool.
