Thank you! Not sure how I could touch on everything you said here-- I can say that the grating sound in Metro is probably a result of my inexperience mastering music. For me it sounds fine, though it's very likely other audio devices don't process the high pitch very well. I actually can't really hear it through the more full portions of the song.
Overall I'm glad that I at least hit the target on the theme. I was a bit worried when I opened up the jam and saw the theme, honestly. I normally feel like I know how to reply to a comment, but you touched on so much here i dont know where to start. Gonna go listen to your OST now though!