Hi Neal,
Regarding the Address (Uri), just put whatever you want like \”null://whatever\”, this is just to give a unique name to the send location (if you use the properties dialog it will add the null:// for you).
Regarding the other problems, sounds like you might have accidentally screwed something up during the change. If you changed all the namespaces for the classes, make sure you also changed the default namespace for the project, as that affects embedded resources (in particular it affects the XSD resource).
Notice that also the NS constant in NullAdapterMgmt.cs will affect the namespace used to discover the send location XSD definition file (SendPortSchema.xsd) from an embedded resource (see above), so make sure those match.
That should be enough to get things going, I think, but if you have any other problem, just let me know and we can work it out.