Creating visual studio C# snippet-like with interface / annotations / reference / using?

Question

I'd like to add a Visual Studio 2015 code snippet or equivalent that modifies multiple places in a C# class. Conceptually I want to have it implement an interface in an existing class.

Creating a C# code snippet is no problem - it will add the implementing methods.

However I'd like it to also:

1. Add a using: using ABC = com.whatever; at the top of the file.
2. Add a reference for com.whatever.
3. Append the interface: ABC.IBar to produce public class Foo : Form, ABC.IBar

4. Add one or more annotation on the class: such as [System.Runtime.InteropServices.ComVisible(true)]

5. Add in some private members just under the existing private members to support the implementing methods, irrespective of where I add the implementing methods.

The documentation suggests that at least the using and reference functionality (first two points) is only supported for VB.

Is there a way to do some or all of that for C# in VS2015? It doesn't need to be with the VS2015 code snippet, but that is indicative of what I'm trying to achieve. An alternative like being able to write ABC.IBar and get a hook for the "implement interface" call would also be interesting.

The fallback is just to do item templates for a partial class, but being able to mix-in to an existing implementation would be very useful.