How can I rewrite a content link and replace spaces with dashes?
The field Link to Content can only link to content lol, it doesn't seem you can override the link URL there (that is why there is no Link path field there, Views interface and features can be confusing at times, you have to know a bit of background to understand the less polished parts). 

You should Exclude from display the Link to Content field, move the Title field down so it's the last field, and unhide it. 

Then you will be able to contruct what you want using the Title field, using the Output this field as a custom link option. 

The option Override the output of this field with custom text doesn't provide the option to Replace spaces with dashes. 

Make sure that the Link to the Content in the Title field is not ticked, and the Formatter is set to Plain text to avoid clashing between different features when Drupal is constructing the output.