COM Interop advice?

Please comment on the following line of thought assumptions (TIA):

Given: I am trying to write an add-in for a COM-based application. Due to limitations in the add-in SDK, once the add-in is written I need to manually add a registry entry for the ProgID of my .Net assembly.

In order to get a ProgID, I need to run RegAsm

RegAsm can either reference the assembly via the GAC or the codebase (filesystem location)

Loading the assembly in the GAC requires a strong name.

Using RegAsm with the codebase option requires a strong name.

In order to give my assembly a strong name, each of the referenced assemblies (including COM interop assemblies) must also have a strong name.

If I use tlbimp with the /key option, I can generate strong-named COM interop assemblies for the SDK type libraries.

When I do this, I am unable to implement one of the methods on a required interface because 'there is no matching sub' on the interface. This is in spite of the fact that IntelliSense detects the underlying method. It is also interesting to note that tlbimp generates a number of warnings while creating the interop assembly.

Apparently, creating add-ins for this application has been done in .Net but I am getting little support in the vendor's own forums. I am wondering if my line of thinking is accurate and if anyone here has any ideas that would help.

Thanks again,
Steamer25