Stephen

With regard to the name, it's just that, a name.  It doesn't have any effect on what the production can and cant be used for.

You can use the foundation production as a router if you want, the difference is that in that scenerio you would be adding all of the components that you needed to the production manually.   Configuring a routing production should give you the basic components needed, e.g., a service for input, a router for applying rules based routing and then an operation.   It provides the basic building blocks needed to route messages.

A generic interoperability production can route messages as well.

A foundation production is a production that is created using the Install Wizard and when created will include some useful business hosts for integrations

Stephen
An Interoperability production is a general integration production, vs a routing production is one that automatically includes some basic business hosts needed for routing messages.

Typically you would use a routing production if you wanted to route HL7 messages, for example.

An Interoperability production is a blank slate allowing you to add whatever business hosts you need.

There is no real difference in capabilities other than what is automatically created as part of the production configuration when it is first created

What does your full URL Map look like?

I would recommend getting your journal drive fixed, taking a full backup of your databases and then start journaling from there.

Whether or not you need the journals depends on how you might be using them 

Obviously they are used to recover your databases since the last backup .

They are also used for shadowing and mirroring 

What kind of error do you get when you try from a browser.

From a browser URL the method is Get.   Is your service Method a Get?

Could also be licensing.