Redline is usually pretty conservative but that assumes an engine in good shape. An old loose engine may not has much safety margin when you hit redline.
I thought these cars had drive by wire, not a cable to the throttle body!? I know the newer ones do so there is no cable to snap.
Get the code read, that is you first and best step. Thne post them here.
Sluggish performance and rough running could be lots of things, like coils, slipped timing, bent valves, clogged smog components, computer went nuts etc.
I would guess coils and from what I have read it is relatively easy but time consuming. I had mine done under warranty. In my opinion the coils are a weak spot in our cars, but I would be surprised that redlining the engine would kill coils, but like I say, I have little confidence in them anyway.
Good Luck, Post scan results.
Jim Henderson
