Maybe you are trying to create new type in approach 1 specifying the full uri? Sorry but you did not paste the url you called. I have always done that by specifying the prefix, try to add a prefix to your namespace in model.xml, and use it instead of full uri.
Also, in approach 1, i think you should deactivate the model you created from share UI.
Look at the logs at startup time too, to see whether there are errors on project startup.