Classes, properties and fields all default to private (not internal).
You also seem to be confusing the concept of folders with namespaces. The "using" keyword allows you to reference classes in one namespace (similar in idea to the idea of packages from java, but not quite the same in implementation). Files in the same folder do not need to be in the same namespace, but certainly if they are ten you can add a single using statement that will add them all.
Code:
namespace Test
{
public class Class1
{
}
}
and then
Also, the feature you are trying to find is "Visual Studio Templates". These can be modified, but I really wouldn't recommend modifying the defaults. You could however add a new template called "Public C# Class" or something.
http://msdn.microsoft.com/en-us/library/6db0hwky.aspx
/- Sam Judson : Wrox Technical Editor -/