Daniel,
We've never tested with Social Fusion and haven't heard of others using it, so I can't really give any good idea if it would work. My guess, honestly though, is that there would be compatibility issues. Since JFBConnect uses an AppId and Secret Key and also has Page Tab support, there's a huge overlap that would likely cause problems.
Multiple Page Tab support is something we're planning to support in a future version later this year. Things always change, but it seems like the right next step for our Page Tab support. Until then, if you really need different applications per Page Tab, you'd need to use multiple Joomla installations.
As for trying, if you want to subscribe, we have a great 30-day money back guarantee. If you can't get it going, no worries.
Hope that helps,
Alex