this app not yet set up

Believe it or not Auto Tune says "all good" & green ticks BUT now there is a 403 error at Remote Error Checker.

If I try to visit your site, I get a 403 as well. If you have a firewall or IP restriction in place, our Error Checker tool won't be able to access the page either. You'll need to disable that, temporarily, to let our tool test and then you can re-enable it.

Attempt to log in usiung FB button in SClogin shows the attached (please see attached) and I'm not sure if that notice is 'friend or foe.' Or how it will affect others.

That login warning means you've setup a Social Profile plugin and are trying to import extra permissions beyond basic profile, name and email. From the image, you're also trying to get status updates from the user. In order for you to get status updates, you need to get Facebook's approval and go through the review process to do so. In the review, just state whatever feature in JFBConnect you've enabled and how the status updates would display on your site.

In securitry at FB for developers is this referring to the IP from which my site originates?

Security
Server IP Whitelist
Update Settings IP Whitelist
I assumed it was so and took the leaop.

You're getting off-track again I'd really recommend getting things setup and working first before you start locking security down. Remove the whitelist IP address and anything else you may have altered to get you back to where you were with the login error message.. then, submit the extra permission for review and test that authentication works and creates users. Then, when things are working, it should be simpler to go through their security checklist to see what breaks when you do and know how to revert it quickly.

Thanks,
Alex