Do you think it's arbitrary to add single shines on the level leaderboards? For example: Bob-omb Battlefield - Shine 1: Any%

yeah I can add them. But nobody ever runs individual shines xD

I guess I will be the first one... well, unless you count people who run this game and don't put it on leaderboards.

I guess I will do them too because these runs will help for segmented speedruns and tutorials.

I also added an IL 100% category where you must collect every star & star coin in the world.

Do I need to have a 100% completed file to do a certain shine?

You only need to have collected this shine already.