The tutorial is outdated. We have since updated the site.
You probably just need to use a different browser.
Your download just isn’t getting the correct extension added to it, which 99% of the time is the browser, keywordinspector is working correctly in Chrome.., if you can edit the filename just add a .csv to the end of it and it will be readable by excel.
Data in our database is updated constantly, the extensive search will allow you to come in each week, every 7 days after a search is created, and it will sync your search results with the newest data from the database.
credits are only used when you create the search and when you redo the search after it expires, so for an extensive search it will expire in a month, at which point you can just leave it or you can spend 3 more credits and have another 4 refreshes of the data.