Hi Ck,
Sorry for late reply to this,
Please find your answer in your queries below :
#1. If I understand correctly, the only way that a user can "connect" their account to FB is by logging in with FB via the module; what about connecting their FB account from within their (Joomla) account settings (similar to the unlink option)?
>> Once the user sign in via Facebook in your site, it actually created an account in the Joomla account.
#2. Can you please clarify if the user has to manually select to share it on FB, or is it done automatically (if auto, can they choose not to share a specific post on FB)? How flexible is the system?
>>Yes, it will done automatically without asking the "choose to share or not", but we will see if we can improve this in the future.
#3. Reading through the EB, ED and ES documentation, they each mention creating a FB app, can one reuse the same App for all of the SI products, or must one create a new app for each product (and have users grant access to 3 separate apps)?
#4. As a follow-up to the previous question,I already have an app configured for Invitex as per their documentation, can I reuse that app, or must one create a new one for the SI products?
>> Yes, as long as the Facebook apps is configured with your same domain name.
>> But in my opinion, if you do it separately that will be better maintenance in your future.
>> One of the reason is Facebook will always update their own API key, I remember previously 2013 Facebook allow every user have this "publish_actions" permission for autopost their status in the user profile page. But last year 2014, Facebook changed their API key again, they don't allow every user have this "publish_actions" permission to autopost their status in the user profile page, only allow SuperAdmin have this permission. So you need to submit this "publish_actions" permission to Facebook for review, once the Facebook approval, then your site user only have this permission.
What I'm trying to say is some of the cases site Admin only allow the user autopost to Facebook page feature instead of their user profile page from Easyblog. So you no need submit for any review in the Facebook.
#5. Must one have SSL configured for their site in order for the FB app (integration) to work? (I know that this is a silly question as sites should use SSL whenever possible to protect customer data, but am still curious).
>> Hmm, I don't think so, because some of our customer site also don't have SSL configured, also can work fine in integration part.