Hard:
HP Drain Rate -2? (So that it is the same as Overall Difficulty.)
0:17:320 - Nc
0:17:720 - No nc.
0:19:320 - Nc
0:20:121 - No nc.
0:20:921 - Nc
0:32:123 - Nc (you done a nc here in insane by the way...)
0:33:123 - No nc
0:33:723 - Nc
0:38:524 - Nc
0:39:525 - No nc
0:40:125 - Nc
0:51:727 - Don't repeat, add a note at 0:52:327 instead?
0:57:728 - Nc
1:07:330 - I can't understand how this can be stacked if 1:04:129 is not stacked. Unstack.
1:09:330 - Unstack, it is confusing.
1:14:532 - U probably stucked not to have a problem with spacing the 3,4,5 but no, it is not helping the player, so unstack.
1:14:932 - Nc?
2:39:748 - Nc
2:41:349 - Nc
2:40:729 - No nc
2:46:150 - Nc
2:47:150 - No nc.
2:47:750 - nc

Insane:
Overall Difficulty +1? (So that it is the same as HP Drain Rate.)
Combos are better in this difficulty! I think that you should see if your Hard has new combos in same places as in Insane; that would really improve hard. I tried to do the job for you above not even knowing about it, yet please do double check! Yet before you do these changes to Hard, please fallow the mod below...
1:10:131 - Remove, you've lost track of the combos because of this evil 1/1 note
1:10:331 - Nc
1:11:531 - No nc
1:11:931 - Make this slider two circles placed where it started and where it finished instead. Then, make the circle you placed where the dead slider finished new combo...
1:12:931 - Nc
1:14:331 - Nc would look expectionaly nice here = not every nc looks nice even if it is right -^^-
1:27:734 - No nc
1:28:134 - nc
1:31:135 (1,2) - Switch their places so that the nc is right
1:55:340 - Iit is definitly nc here like on all the other ones!
1:56:340 - No nc
1:59:741 - Maybe add a note?
2:07:342 - Nc here like on the previous one of the kind.
2:12:143 - Nc?
2:13:743 - ^
2:18:944 - Nc
2:19:344 - No nc
2:19:745 - Nc?