Auto login is a setting in Filemaker Pro when you design the databases, you will have to change the setting in filemaker pro. Under the File menu, select File Options, then uncheck Log in using. This will require the user to login.
You setup users File, Manage, security.
Layouts can not be modified in Go. http://www.filemaker.com/products/filemaker-go/docs/techbrief_filemaker_go_11_en.pdf
In Filemaker Pro you can hide the Toolbars with the Show/Hide Toolbars script command. Show/Hide Toolbars[Lock;Hide].
With the comibination of scripts and security you can prevent user from modifying the layout in Filemaker Pro.