For the intro I suggest following the vocals and only the vocals as the piano has a bit much going on and the vocals clearly cut through the instrumental as the most important sound. For the snippets of things like 'Ichi ni san' you can simplify it to 3 1/1's
if you are going to keep some of the rolls make them full bars:
ex. 00:28:501 (32) - extend to 00:29:405 and remove plet
00:49:321 (18) - is also an acceptable one to extend to a full bar as it emphasizes the same sound as the previous.
For the Verse before the Kiai it could look a bit more like this -> https://osu.ppy.sh/ss/19507730/0175. Where it's mapped to vocal and simplified to leave more density to our Kiai and keeping the patterns simple enough for a beginner player.
For the Kiai you can follow the snare and downbeats, then add in the vocal chop of "hey" in the later half. It can be colored to follow the bass on the root note. first part https://osu.ppy.sh/ss/19507740/2b36 , later part https://osu.ppy.sh/ss/19507741/4951. Feel free to figure something else out too!
The first part of the outro is effectively the same as the verse before the chorus so I would recommend doing something similar there.
These rolls either need to be 1/1 space from previous and latter notes or not utilized as it's currently too hard for a shokyuu and can be emphasized with plets instead
00:28:501 (32) -
00:44:949 (18) -
00:49:321 (25) -
00:52:344 (29) -