Rubio is already weak in Florida so I don't think Kasich's performance sways much there.
Kasich's the only one that Trump hasn't launched a barrage of childish personal attacks against yet (mainly because Kasich hasn't presented a threat), so there may be an opening for VP.
It would be in Kasich's best interest to accept any such offer.
Kasichs positions on some serious issues run counter to Trumps.I don’t think Trump will pick him especially if Trump sees himself taking Ohio.