It will be a Trump/Kasich ticket. Dr Carson could be SOS or some other high ranking post in Trump admin. Kasich is not attacking Trump in any vicious manner. And Trump has not attacked Kasich for months. Kasich is staying in to foil GOPe Rubio. Main negative on Kasich is amnesty agenda, but as VP he will not be calling the shots, and he will be most helpful in Ohio in November.
Kasich is probably exercising shut up because he is worried about this kind of thing on a bigger scale in his state at the convention.
I can hear Ted Cruz now saying “ A Governor is responsible for what protestors do in his state. Gov Kasich must have had the wrong tone and encouraged violence”.