Are there any defaults in the clickonce installation?
If someone decides to install the application, this application will be availiable to all the users of the computer?
I guess the answer is no. They can only use the application if they log into the user account who installed it… but sometimes it is better to ask
No, according to this matrix in the Microsoft article “Choosing Between ClickOnce and Windows Installer“
“Install for All Users” is not supported. As said in the article (emphasis mine):