For most of the show's run, Clark was just a kid trying to hide the fact that he was different and learning about responsibility. There was a lot I liked about the show, but that all ended when Michael Rosenbaum left the series and the focus shifted to Metropolis.
The transition was too jarring, almost like a different show altogether. Keeping Clark out of costume minimized this, but it wasn't enough. It would have been far better to change the show's name and resolve his ridiculous fear of flying with the first episode of Metropolis. I'd have brought back his father's ghost briefly- a way of connecting the two shows while saying goodbye to the old- and given him the costume and cape right away.
That would have made the changes more acceptable, while at the same time diving all at once into Clark's new role as Superman, hopefully extending the life of the story. But I guess it was time to think about another movie anyhow.