The notes from the timpani are actually in the chords already, and it sounds kind of weird if you try to double it up in other octaves... I did add accents and a crescendo at least
You're absolutely right, once again I've wrongly assumed that a song loops
I think adding octaves to the second voice would make it really difficult to play (especially if you also try to hold that half note), and the octave on the very last note does a good job of "popping" the end of the section. As for the crescendo, I honestly feel like the song enters a relatively light section in measures 7 and 8, and a crescendo would kind of contradict that attitude. I also think the mood on certain beats (like the feeling of "surprise!" on measure 7 beat 4) is somewhat emphasized just by the added harmonies.
You're right, the grace notes were totally bad lol. Changed it to only the top of the harmony. If you also meant the LH 32nds, I think those are more necessary but should be easy enough to roll across the hand.
I suppose a legato marking couldn't hurt
Couldn't find a reasonable way to incorporate the arpeggios themselves, but I picked some notes out of the chords they form and added harmonies. The section did sound pretty thin before, hopefully now it's slightly better
Yup, dun did it
The drum solo:
Honestly, it's pretty boring without the snare rolls involved, and those aren't really something the player can just do idly with their other hand. The song repeats remarkably well without that section too, so I'm inclined to leave it how it is