It sounds great, but we've been up this railroad before. The 3-C Corridor seemed so certain that mock timetables were already circulating, showing several frequencies per day, and even some early morning or late night trains that started or ended in Columbus. The rallying cry during the campaign of a now former Ohio Governor was "That Train Is Dead", and he stuck to his word.
As for Cincinnati-Indianapolis-Chicago, this would essentially be a longer version of the former Hoosier State. And we know that without state support from Indiana, that service met its unfortunate demise. An extended version of the same thing would still need state support, and I doubt that Ohio will pay for Indiana's portion.
In talking about Cleveland-Pittsburgh-New York and Cleveland-Buffalo-Albany-New York, those become fairly long routes and they will need some heavy tweaking of schedules. Cleveland-Pittsburgh-New York would essentially be an extension of the present Pennsylvanian. On its current schedule, based on its current westbound arrival into and eastbound departure from Pittsburgh, the calling times in Cleveland would become unfriendly to be an attractive alternative. Cleveland may be used to poor times, but if Amtrak does become willing to start new long distance trains, it does fit nicely into an overnight schedule, with an evening Cleveland eastbound departure and a morning arrival in Philadelphia and New York. Sleepers would be needed for this. But then the argument may be raised, why not continue this train all the way to Chicago to provide a new frequency?
Cleveland-Buffalo-Albany-New York brings the same thoughts. They would probably take one of the Niagara Falls trains and extend it to Cleveland, although that train would now miss Niagara Falls and only stop in Buffalo at the Depew station like the Lake Shore Limited. Again the route almost becomes too long for a day train, so it might work well on a new overnight frequency across Northwestern Pennsylvania and Upstate New York, fitting in with an early morning New York-bound departure from Albany and a late evening New York-Albany train.