Obito awoken his Sharnigan with 2T and when him and Kakashi unlocked the MS, it pushed it to 3T.On Kakashi. We actually can’t confirm that. When Obito gave him his Sharingan it was only 1T and we never got to see Kakashi Copy any of those 100 Jutsu so we can’t be certain on that.
However I can give you the 2nd point. It probably would have been better to go that route. But like Boruto’s mutation in his Byakugan, SP is probably going to add some new things to 2T and 3T. I’m not thinking Susanoo or Amateratsu but something in line with her genjutsu affinity. But your point is a valid one nonetheless.
Whatever happened to Boruto's eye thing though? They kinda dropped it after the first arc.
I hope they don't do that with her Sharingan, like save the crazy bullshit for when she get's her MS, we all know she will.