Major change with MKPC that would be for the best!

1.Currently, CPUs are programmed via route. However, In mariokart 8, They seem to be programmed specifically to only hit all the checkpoints and not follow a specific route. I think programming the CPU AI to do something similar to that would be better.
2.Items are determined by frequency, and place. However, Mariokart 8's "Units from first place" would make it more fair. Also, the feather would allow for a lot of creativity in custom tracks i think it should return lol
3.mission mode needs to return too

My thoughts on it:
1- That would be really bad for older complete mode Tracks, since, not all of them actually have organized checkpoints and with that, the CPUs would crash on walls, fall in holes and other things, yes we can edit the Tracks to have more checkpoints, but some of the old Tracks' creators wouldn't be able to do that because they don't come here anymore/are not as active as they were before
2.1 (item distribution)- It would be cool having it, but I would see that as an alternate distribution setting rather than making that the new base distribution for the game
2.2 (feather item)- Yes, it could be used for cool gimmicks on specific custom Tracks, the problem is the ones that this would just break the Track, for example, Tracks with walls, if you could just jump it whithout having to care on what's happening in the real Track, why would you race on it?
3-Challenges exist and yeah, there's none for the base Tracks, but for that just find the Tracks remade by other people.

Peach Gardens:

Items are already determined by the position of the racer and the distance from first

The only place the feather would work is in battle mode due to the way checkpoints work in this game, and still that would mess with the item distribution

It already exists, it's just called "challenges"