Selwyn (or anyone else in reading through this thread),
It's probably best to start a new thread for new questions about integration with Virtuemart. This thread's become a little untamed with discussions going in new directions. However, as to your questions:
1) Yes, we've tested JFBConnect quite extensively with Virtuemart and think it's working well. We're helping a few users in this thread work through some teething issues, but so far, nothing's been directly related to JFBConnect. However, please note that the current implementation of Virtuemart integration requires the Full Joomla User setting in JFBConnect, which will present a shorter registration form to the user. That's simply because to create a user in VM, we need some specific fields filled out, and it's information we can't get from Facebook.
2) As with every extension, there is a little overhead, and there are lookups to Facebook both server and client side. This will slow things down. However, it shouldn't be noticeable in really anyway. With JFBConnect in general, we rarely (maybe ever 3 months) get posts about slow-downs. When we do get those posts, it's usually do to a site configuration or server issue.
3) The Like button is not automatically added to products yet. We're working on adding this ability, but for now, it's easy to use the {JFBCLike} tag in the VM template or description for the products, or the JFBCLike module for VM menu items.
If you have any further questions, please start a new topic
Thanks,
Alex