[General]
Nice song choice...
BPM 105.140, offset 16865. Maybe not very accurate but should be fine enough.
Naraku's Insane, who is Naraku? (check tags) Add narakucrimson to tags.Also if i don't remember it wrong, it's in the album <Hybrid Theory>, so add that to tags too.
why your HP bar is so short?

I feel it's really not so good when i hear the clap pace is broke again and again in several places . If you want to use that clap you should arrange your beats partly based on it, if you miss many it sounds really not like a constant drum beat.
[Easy]
02:09:851 - i think you should start the soft hitsounds from here, could add whistle at (2)'s beginning and repeat point. remove the clap if you do so.
02:19:553 (1) - too loud
02:24:404 (1) - start 1/2 later.
[Normal]
01:12:209 - add a note here, it's important (clap)
01:23:623 (1,3) - don't forget clap at the beginning
01:46:737 & 01:47:878 - add notes if you want
02:05:285 (1,2,3,4,5,6,7) - the combo is a little long...?
02:09:851 (2) - same suggestion as Easy, start soft hitsounds section here.
02:54:937 - add a note
03:04:069 - add a note
[Hard]
00:32:699 (1) - the vocal is there but i think it's better to move it 1/4 later because it's the place are being expected imo.
00:34:554 - the clap miss sounds really weird.
00:52:960 - should add a note if you want to follow the vocal
01:24:778 - clap miss
01:27:060 - ^
01:32:625 - should be a note here?
01:33:196 (2,3,4) - this looks not so good, why not copy&paste (2) as a (4) and keeps the same spacing?
02:22:135 (1,2,3,4) - you could just use 4 1/2 slider here, lower the volume if you don't need the sliderend sound, but 2 & 4's end could keep your clap pace.
[Naraku's Insane]
very nice diff.
02:42:391 (3,4) - the only thing i'd like to point out is her...i don't think this 1/4 makes sense... the long "know" is obviously start from the red line... so what's this for? if just for the placement, i think you may doing in a wrong way...
well another thing @Roddie: There's several soft-sliderwhistle used in this diff but i think it's unintentional, so you may want to add a muted soft-sliderwhistle.wav file in your folder, it's easier than fixing them one by one.