[General]- Hm, I think you should reduce OD of insane down to ~7.7 or so since there's still a fair amount of LNs compared to notes.
- OD 9 is probably pushing it too far for a difficulty with only 7 notes per LN. Maybe ~8.5 is better?
- Your soft-hitnormal is really quiet. I'd consider amplifying it by a few dB in audacity.
[Easy]00:16:420 - Add a note here to signify the tom? This is due to it being the transition into a next section, and also to differentiate this sound from the other simple 1/1 drum sounds.
00:27:464 (27464|2,27794|1,28123|2) - This is more of a visual thing looking in the editor, but control H to avoid 00:27:464 (27464|2) making a shield with 00:26:805 (26805|2) when they aren't the same pitch?
00:27:629 - and since the kick here seems fairly loud, I'd consider adding a note here.
00:32:244 - ^^ This way, it adds a little more variation to the map and can be a bit more challenging to beginning players.
01:07:025 (67025|1,68343|0) - These are the same note so remove 01:08:343 (68343|0) and extend 01:07:025 (67025|1) to 01:09:662
01:09:662 - So this is where a few more parts are added into the music, and I think the mapping should reflect that, so why not add notes at places like 01:10:321 - 01:11:475 - 01:12:959 - 01:14:112 (and etc.) to represent the hihat crunch?
01:20:541 (80541|0,80871|3) - Jack these since they're the same pitch?
01:25:816 (85816|2,86145|1) - ^^
01:32:244 - Consider adding an LN from here to 01:33:398 to represent the 1/4 drum rolls and synth. This measure already feels pretty empty.
01:43:783 - Add a note for the kick here to differentiate it from the rest of the measure?
02:01:915 - Just a visual suggestion, but try this?

[Normal]00:34:717 (34717|0,35047|1) - Visual suggestion, control J?
00:47:244 - Why not make the notes in these measures doubles like you did at 00:06:365 ? The sounds are slightly different, but I think they're both heavy enough for two notes.
01:37:354 - This measure is very similar in of sound to 01:34:882 or 01:32:244 so why not use an LN to represent this measure instead of mapping actual notes?
01:38:673 - If above is accepted, make this a double for the clap?
02:12:052 (132052|2,132134|3) - Since this is 1/4, consider moving it to two hands instead of one since it kind of came as a surprise to me since I don't think you've used 1/4 at all in this diff until here.
[Hard]00:16:255 - Yay, visual suggestions again. But honestly, I think this is a little easier to read than what you have now.

00:26:805 (26805|0,26887|2,26970|1,27052|3) - And maybe try making this a 1 -> 4 roll instead?
00:36:942 (36942|1) - Why not start this burst as a {43}{12} burst? So it'd look something like this instead

00:56:475 - I just made a realization. Why don't you map the 1/4 here and at 00:14:277 but you mapped it at 00:36:860 ?
01:40:651 (100651|3) - This LN is actually only 1/4 long because there's another synth here at 01:40:733
So the only real problem I noticed with this diff are the inconsistencies of what you choose to map and what you don't, like the drum rolls I mentioned above, and also the toms at 01:50:871 - 01:50:953 - 01:51:283 - which you mapped in the beginning at 00:15:926