To chip in on the initial problem you were trying to solve. I had exactly the same issue, whereby submitting the edited form resulted in the form being redisplayed without saving, or error. I added a bit of debugging to chunks and snippets and discovered that the conditional output modifiers for the error messages weren't behaving in npOuterTpl. For example:
Even though np.errors was not empty, it wasn't being rendered. I've removed the conditions from the placeholders and the reasons for the form not being saved are now being displayed:
I've noticed inconsistencies between installations or versions for conditional output before, but nothing that I could explain or be bothered looking into. Anyhow - looks like I have NewsPublisher working as I want, I just need to remove the validation for 'content' not being present (intentional) in my edit form!
Thanks both for your contributions