00:13:703 (5,1) - watch out for slider overlaps (especially for low difficulty maps, they look ugly)
00:16:772 (1,3) and 00:16:991 (2,4) - either make these more stacked, or further apart; this sort of stacking usually looks ugly (applies to this)
00:16:777 (2) - This is very awkward. The spacing needs to portray the timing for the note. I'd recommend moving it closer to the following hit circle. Something like https://imgur.com/a/luyc7VU this would work well here.
00:18:526 (1,2,3,4) - if you're gonna make a "burst" it has to be clear in a difficulty like this. it is extreme hard to see even for me how many noted are layered here without looking at the approach circles. stacking them properly will make it much more clear as to how many notes there is for the player
00:19:403 (1) - end the slider at the previous blue tick (00:19:732) and place a circle at 00:19:841
this represents the vocals and the drums instead of overlapping the vocals
extra for 00:19:403 (1,2) - i'd ctrl + c and ctrl + v one of these to replace the other first before you apply the changes mentioned in the original post
00:22:034 (7,8) - these two notes should have equal spacing with the slider to respect the timing. Like this https://imgur.com/a/s7cDNgE
00:25:541 (1,2,3,4,5) - for a hard difficulty, burst like these should not be seperated, let alone be a death stream. they should be ordered like 00:18:526 (1,2,3,4)
00:32:557 (2,3,4,5,6,7,8) - same goes for this, but replace this stream with a few reverse sliders
00:29:043 (8,9,10,1,2) - Same with these. They are all a fourth beat, but their separation is not equal. While yes, you can have objects with differing distances with the same timing, this isn't a situation in which you should do that.
00:32:546 (2,3,4,5,6,7,8) - I'm gonna be very blunt here, this looks really bad and should never be done. I'd recommended remapping this whole section, as currently u are not respecting object distance vs timing. If you really like the stream here though, you could potentially do something similar to this https://imgur.com/a/YTZxfBu
00:50:612 (9) - this needs to be a quarter beat to the right on the timeline. 00:50:283 (7,8,9) - This whole section is very cramped, id recommend rearranging your objects here. I quickly made this https://imgur.com/a/D5e6au7, which feels a lot more playable
00:53:567 (7,8,9,10,11) - this section is very cramped. I personally am not a fan of 00:54:005 (10) - this slider being in this stream, it makes it very awkward to play.
01:59:262 (9,10,11,12) - My personal preference is to not map vocals that don't follow a rhythm at the end like this. You should think about using a spinner or just not mapping them at all.