Right now 0 stars and 1 stars are in the same categories but I think it would make more sense to put them in seperate categories.

The reason they aren't separate is because getting the red coin star in Bowser's Tall Tall Mountain is about the same speed as doing the bully clip to skip the red coin star. I think the current consensus is that getting the red coin star is faster than skipping it, so the optimal any% strategy for the game, as far as people who run the game are concerned, is to do 1 star.

So while technically the game can be completed with 0 stars, we can save time by collecting a star, so in a "0 star" run, the best thing to do is collect a star.

Unless you are suggesting that in the rules of 0 star we specifically forbid people from collecting stars (like a low% category instead of an any% category), it makes no sense to split the categories.