For wave sliders (such as 00:04:785 (4)) it is better to have the set of anchors parallel to eachother (https://osu.ppy.sh/ss/15943799/85af instead of https://osu.ppy.sh/ss/15943811/0c14)
When making sliders like at 00:03:713 (3) try and use the grid snap tool to make both sides symmetrical, and then rotate it afterwards (https://osu.ppy.sh/ss/15943830/ea05 ---> https://osu.ppy.sh/ss/15943833/60ca)
I dislike the use of perfect stacking used in the map (00:01:303 (1,1), 00:05:588 (5,1), 00:09:874 (5,1), 00:36:124 (1,1,1,1,1,1,1), etc.) as it doesnt necessarily fit any aesthetic sense that I could find in other parts of the map. You could add some spacing manually between these sliders (https://osu.ppy.sh/ss/15943850/6e19, https://osu.ppy.sh/ss/15943853/0d7f)