OK it's a good thing this is just a beta because they seriously fucked this up lol
First off, we have a clear example of why it's stupid to have gameplay benefits based on what characters you have:
Literally everyone in an online race will pick the same character and why wouldn't they? Most courses only have one or two favored drivers and you can't pull three items without them. Karts/gliders thankfully have no benefits since MP wins are based on position, but since the selection screen is the same as always, people are naturally going to pick the quickly available ones instead of slowly poking through their inventory.
Secondly, three items make things way too hectic. Mario Kart is wild with one item each, it's wilder with two items each, but when you're on DK Pass R, the favored driver is Dry Bowser, and everyone in the back is pulling multiple Bowser shells every 2 seconds, skill just straight up goes out the window.
Two items should be the standard, and it would also prevent frenzies which are unsurprisingly awful in MP. I played a friendly race against jadedpony where I had a bit of a lead going into the second lap of New York Minute 2 and pulled a coin frenzy. What were they supposed to do? I turned invincible and got to cut corners in the park to go even faster while I was already winning. There's no counterplay to that.
30 minutes for cup rotation also seems a little long assuming cups have 3 tracks like in single player. Why not just have it randomly rotate through every track available? At least the connection seems pretty good, it's not laggy or anything. I can see this being a big hit if they make some easy fixes.