Hello in this situation who is the admin I need to talk to, as I still can't submit 

same issue here, and I'm using a personal development instance.  I can confirm on a paid servicenow instance I am able to publish the application.

However, I have to point out that the purpose of a developer instance is to develop apps in a full lifecycle.  Why would they hinder it like this?

The main reason for it not working on a PDI is that you only have one instance in a PDI stack and don't have access to push things to the app repo. In a customer instance stack you'll have 3+ instances so there's somewhere for the app to go.

Does this mean I cannot test out the solution in a customer instance where I am using dev and test. The test instance will act as the production instance. 

Customer instances should be connected to the repo so you'd be able to move the apps. PDIs (devXXXXX.service-now.com) are not connected to the app repo.