Picking your top posts and pages and optimizing them as much as possible from search console data.
This search console data is faked data in the image if you can get a 70% CTR in search you are one hell of an SEO o an SEO Expert In Search Console.
Yes very much as you will see any errors your site may have in the search console. However, you may have to use additional tools to find exactly what is causing errors and harm your SEO. It helps in building internal site structuring by giving data about the internal linking which you should be using on your site. Building links can lead to increased rankings in Google Especially.