I'm not sure I like 'fade in' being used instead of a dynamic marking, even if it captures the intent quite clearly. I think moving it above the stave (and right of the tempo) and adding an actual dynamic would be best, would you agree?
I think I like its positioning centrally next to the crescendo where it's most apparent and where you'd expect the opening dynamic to be. I'd prefer to keep it, but if you feel strongly I can just change it to ppp or something, shouldn't make a difference in how it's performed
m5 & m7: I think I hear the F# be restruck at beat 3.75, though it's not entirely clear in m5
I don't think I hear either, at least nowhere near as apparent the restrike is in m. 10.
m8: Thoughts on including the mallet figure in the RH?
Good question, let's see...

The first couple of notes just octave double the left hand, and it's a bit of an awkward jump to the high E, and that's getting into the range of the main melody so I think it'd distract from the incoming main melody more than I'd like. I'd prefer to keep it out for these reasons!
m17 beat 3.75: You could include the low E in the RH here, to keep things moving
That makes sense, similar to beat 3.5 in m. 15. Updated (and m. 21 similarly)!
that's all, but next time transcribe the wave sounds
check out
this sick sheet of mineFiles updated, thanks for checking!