Good stuff. One suggestion, especially since you mention deploying to many servers. Remove the :setvar statements, and declare them externally (probably as environment variables if you're going to run this from SSMS). I've done this with "build" scripts created from Visual Studio. I have a .bat file that executes the scripts via SQLCMD, and cycles through my servers executing each script.

Using SQLCMD mode from SSMS is nice in that it gives us the opportunity to test the scripts before putting them into production.