Alright, random modpost cuz I can!
[General]
Delete .osb files and full submit if you aren't using a storyboard or the same storyboard across all difficulties.
The artist should either be ROUND TABLE or Round Table, not a mix of both.
Taiko_BG.png is over 1.00MB; not exactly sure if this is an issue.
[SK's Easy]
The intro has 0.8x spacing, whereas the verse has 0.9x spacing. As an Easy diff you should maintain one spacing. Also, consider this: 0.8x to 0.9x is an increase of 12.5%.
00:40:455 (3) - 1.10x spacing, too much for 0.9x Easy.
00:46:806 (3) - NC
00:48:621 (1) - RNC
00:50:436 (2) - NC {these three to make NC start on "Let me be with you", since it's pretty significant}
[Nich's Normal]
00:01:438 (1,2) - Compare this stack to what you have at 00:08:696 (1,2,3). This goes half as fast, and may confuse newer players. Then you have 00:16:409 (1,2) (which will hopefully be unstacked; look at next point), and 00:50:209 (3,4), which is the "faster" stacking. You may want to change this so that it doesn't stack.
00:16:409 (1) - Even at this AR, the approach circle may be confused with the spinner circle. Consider replacing off to the side retaining spacing.
[Mythol's Hard]
00:06:882 (5) - NC for "Let me be with you", since you have it everywhere else.
00:21:400 (5) - NC for the "baby baby" that stands out?
00:32:061 (3) - It appeared you wanted the first part of this slider to be (2) rotated 180 degrees. Here's a quick slider fix for it to look a bit more tidy (you may have to reposition (4) to maintain spacing though):
376,48,32061,2,0,B|340:72|336:124|336:124|332:160|348:196,1,160
00:43:177 (3) - NC since it makes most sense musically, and this really does not look like a continuation of what you have at 00:41:362 (1,2).
01:01:551 (2,3) - I think this, 01:03:366 (2,3) - and 01:08:810 (2,3) - are undermapped. Looking back at your other "ooh ooh"s, you've got more interesting patterns consisting of short sliders, circles, and kickbacks. Of course, if you've got any musical or reasonable excuse to keep these, do share.
[Insane]
00:46:579 (6) - Starting with the "yeah" with a lone circle, the next two "yeah"s until the "let me be with you are represented by a stack. After that, at 00:53:838 (1) - you represent the "yeah" with a slider, but you have a stack at 00:55:653 (7) - and a lone circle at 00:57:468 (6). For a quick fix, I would change 00:57:468 (6) - into a stack to match the previous line: something like this?
http://puu.sh/s2ph01:01:097 (6,7,1) - For the same reason, I would remove the stack (7) and reposition the (1).
01:02:912 (6,1) - And I would stack this and add a (7), seeing how you followed the pattern with 01:04:727 (6,7,1) - . Apply this to 01:10:171 (6,1) - as well.
01:12:213 (1,2,3,4,1,2,3) - This parts ends the Kiai section. Seeing how the Hard diff even had 1.5x spacing, you may want to consider an increase to 1.25x spacing to this section, then the last three circles even greater spacing. The way you have it does not see climatic enough, to put it one way.
After this, I'm not quite sure what pattern you may or may not be following, but I'm wondering when you decide to use triples and when not to... the randomness doesn't quite make sense.
[NoHitter's Taiko]
01:28:545 (1) - I know what you tried here, but the spinner doesn't really work here. You should have just a D here; music doesn't change from 01:21:286 (1) except for the background being taken out.
Good luck :3
Really, i think this isn't a big problem, but will change this if it bother everyone.