Sorry I’m late. You’re incorrect.
The monitors are not touch screens; they’re just regular flat LCD monitors.
The monitors have a little touch strip on the side of their frames. Vanna touches the strip which is like clicking a mouse, telling the screen to advance to the next screen, which is the letter. Vanna doesn’t even know what the puzzle is, she just touches the little strip on whatever monitors light up.
And the producers never for a moment have considered anything that would remove Vanna from the show. They’re like a big family, for the most part: the production staff has pretty much all been doing the show for a couple of decades. Heck, I’m just a guy in Vegas, and I’ve been working on the show for over a decade when they come here. They’re very loyal, very professional; basically just great people to work with and for.