Hi! I think that your plugin is perfect! But before finding it, I've tried different plugins and now I think that one (ore more) of them have messed up all the configuration. I'm not a programmer but from Facebook Debugger it seems that your plugin haven't written anything over the old plugin settings.
For example look at this Facebook Debugger page for one of my page.
If you look at the og:image it links to the old link of the old plugin I was using: http://www.millerpictures.it/wp-content/uploads/2012/06/Facebook-Meta-Tags.png
The old plugin's name (that I've already deactivated and uninstalled) was Facebook Meta Tags.
In other pages, things are still not working correctly for other errors: this is the home page.
I know that maybe this request is a bit too much, but can you please help me fixing all the errors of my site? If you can't, just tell me what do I have to do in order to fix this.
I'd really like to make a donation to you if this plugin finally solves my problems, and I think it can make it. I always do this for the free plugins that help me with my website.
Thank you very much for your help.