No. The Application is free of charge.
In most cases JetBrains Toolbox App can detect these IDEs and work with them, without supporting certain features. However, if you decide to stay with JetBrains Toolbox App, we'd recommend uninstalling these previously installed tools and re-installing them through the Toolbox App.
Yes, it will.
Default locations depend on the operating system:
All downloads are verified to come from downloads.jetbrains.com and https is used in all communication.
Yes, it does. Click the metal nut icon on the right-hand side of the IDE whose configs you want to edit, and then select Settings.
The extension can only access the current page you are visiting and works exclusively with github.com. It needs this access in order to determine the structure of the project file.
The application sends usage data only after your explicit consent. On the server side we use a query string to detect download requests originating from the application.