a. the SVC software is ready to receive information from facebook (and any other platform like Joomla, WordPress or custom code) will request an example below
b. this is already possible with the SVC core but due to some unfinished coding hasn't been released yet. You can use a list of online users and call anyone with a click, there is a built-in list in SVC (flash). The online username can be called via 3rd party script (php sample and WordPress plugin will be provided) that gathers online-user data directly from the database. Expected in early 2012.
c. I don't know about this one, you should contact the seller
Is there a way to just have people that come on a website be able to get on the chat? I don't want to have random chats. Just specific people that are invited.