ASP.NET application file, provides a way to respond to application or module level events in one central location. You can use this file to implement application security, as well as other tasks.

I doubt it, but it should not matter. To elaborate, this is ASP.Net 4, I do not upload a dll to winhost. Instead I upload the .aspx and .vb files, and IIS compiles everything on the spot, creating a ...

Test, test and test again. You can automate those tests with a TestServer-based Web app that doesn't even touch the Web server. With the advent of ASP.NET Core comes additional automated testing ...