03:38:867 - note here to follow a structure with the vocals where they all do 3plets? if you change 03:40:411 to kkd it also adds some nice contrast to the ddk that comes up later
and since you were following strictly the vocals in this little break i think you can remove 03:42:617, keeping 03:44:382 to define the break should be fine though
same for Muzukashii