If I can just amend my above post - it seems the images are now being picked up (maybe my cache was interfering with getting a true reading from my site when I first tested it after installing JFBConnect) so that is great news!
That is great news

The Open Graph Debugger that you're using is the best tool to force Facebook to re-fetch your page and update their cache. If you don't use that, it can take Facebook 1-2 weeks to automatically scan the page and detect the new tags.
As to the errors you noted, can you let me know what specific URL you are testing? I just tried on a few articles from your home page and each had an og:type, image and I couldn't find the mis-matched tags.
In general though, JFBConnect tries to automate the process of tags as much as possible. We have specific Open Graph plugins that can help automatically set the image and other data for specific extensions as well. Even without a plugin for a specific extension though, it should just work. For critical pages, there are ways to set/override the tags individually so that you can curate pages exactly how you want them to display.
For more information on how to do any of the above, just let me know. And, if you're still having those Open Graph issues, just let us know the URL.
Thanks,
Alex