Some form fields I want hidden on the form (done) but visible to edit in submissions. Is this possible?

I understand that you want to display the hidden fields when the submission is being edited. If so, you may achieve this requirement by using the Get Form Page URL Widget and setting up a condition to show/hide the fields on the form. 

I have a form with radio button field to be displayed on Edit submission.

I set the condition as shown below to display the radio button when the form URL is containing 'edit' text i.e., when the submission is in edit mode.

Please check the screencast below to see how it works.

Here is the demo form that you may check and clone to your account as well.

https://form.jotformpro.com/72241832725959

Hope this information helps! Let us know if you are referring something different. We will be happy to help.