Basically, Mario Kart Wii was the perfect game
Sorry but no, and just to illustrate this point, I'll actually build off of the things you mentioned so far:
- Kart momentum is horribly gimped. As much as you can say that it's more realistic for a car to bank a wall and lose most if not all forward momentum. I don't think one should strive for realism in a game where we blast things with lighting bolts at will. On top of this, the game feels slow for some weird reason. (Unless of course you're [tornado fang]ing Baby Luigi in a Bubble Bike.
)
- Player AI takes a level in mind racking after 100cc. (It's funny because this used to be an issue I heard a lot of back in the MK64 days, but it's actually only true in the case of MKWii)
- Online mode has race breaking flaws. This is more due to issues with latencies, slight lag between players and a number of other things, but dammit, if I shoot a shell at you and can see it connect, your ass better not just drive away with a troll face on. This issue also extends to massively cheap tactics like insane Bullet Bill spam by multiple characters in the third lap.
- Speaking of issues with items... CLOUD AIDS, CLOUD AIDS, CLOUD AIDS, on top of mini nuke Blue Shells. (Bring back the Spiked Shell turf cruisers!) There's also a massive discrepancy between offensive items. Seriously, people can shrug of banana peels so effortlessly, there's no point to them. Fake item blocks got gimped in an interesting way by having their colorscheme changed. Seriously, everyone can tell what they are now. Also, I'm still insanely PO'd that they kept the "you can't hold onto your items once knocked out" thing that DD & DS introduced.
- Several levels in the cups for past games are tweaked to the point of being unnecessary.
And yet for all the bitching it sounds like this post is, I still enjoy MKWii a lot. I haven't played it as much as I thought I would, but it's still pretty good for racing every now and again.