UA is obviously not adding TATL service from CLE. At least not under current UA leadership.
I can't imagine any UA leadership adding TATL without re-hubbing the city. And they're just not going to do that.
Frankly, absent a (stupid) subsidy, I don't see any foreign carriers opening the route.
Maybe the gulf private jets coming to the Cleveland Clinic will sell passage to make up for the reduction in oil prices
As for the facelift, I think aside from a new coat of paint, the only thing the airport should be doing is paying down their debt, and rebuilding the rental car center ON the airport.