GD need public app?

I’ve been using GD social importer fine during development but now that I’m releasing and adding other users I’m having some issues.
Two questions:

– am I supposed to “Make GD app public” rather than in development mode in the facebook app review portal? If so, what does this really mean in GD case, as I don’t think any FB user will ever access the GD “app”.

– Separately I use the Facebook login feature of my theme. For this I have created an different facebook App ID (that provides access to name and email address from FB). This then is a different App ID from my GD App ID for these settings. Is there any problem using two different FB apps on the same site? One is used for authentication and the other for FB page import so seem to be different but not sure if allowed.