Professional or exhibition matches are NOT scripted. But, that does not mean they are pre-determined.
It's nearly impossible to script out a complete match from beginning to end. Too much can go wrong.
Management has a wrestler they want to 'go over' in a match, so they will instruct the opponents of how it is to end - and if certain elements MUST HAPPEN (outside interference, specific moves, etc.) But, its up to the wrestlers to work out the details and know what they can or cannot do.
The more experienced wrestler (often the Heel) calls the match, setting the pace and tone and deciding when to create heat (the Heel cheating) and when to wrap it up.
There is no actual script.
And wrestlers do get hurt, sometimes seriously. The injuries and risk are VERY REAL.