I have some concerns about the OD and HP of this set:
First of all I think the OD of the kantan should be 3 instead of 2, the futsuu-topdiff is 4-6.5 so there's no reason for the kantan and futsuu to have an OD gap of 2 (2-4).
I also think the HP of the kantan should be 7 -> 8, futsuu 6 -> 7, muzukashii 5 -> 6, oni 5 -> 6. Top diff could be hp 6 -> 6.5 but I think HP 6 would also be acceptable.
The oni OD could be raised to 6 because the top difficulty is OD 6.5 but OD 5.5 would also be acceptable IMO.
go to your .osu files, under [Events] change the last zero on " 0,0,"bg.jpg",0,0 " to like +90(fits for me), that way you can center the character on the background to fit the playfield. this is also given as a guideline in RC: "Avoid covering essential parts of the background with the taiko playfield."
You have 1ms unsnaps and some unnecessary green lines, although its not a gungacritical real problem you can hit map cleaner on mapping tools and get rid of them easily and you can prevent issues like sv, volumes not applying etc (https://mappingtools.github.io/)
hp/od
the muzukashii and futsuu definitely need an od boost because of their high density, od3/4 is really low. after making this change you will face an issue of having a kinda not linear hp spread so i'd suggest this difficulty spread:
kantan od3 hp7 - hp7 cause you have a lot of notes
futsuu od4 hp6
muzu od5 hp5
oni od5.5 hp5
inner od6.5 (maybe 7 is better but it depends on your liking) hp6
you have kantan and oni as collabs, but the writing of the collab diffnames are completely different? which is very misleading imo (one is with feat. and the other with &). My suggestion would be picking one style and going with it (mapper & mapper2 seems good to me)