Be-Regarding private mail. It is available to all during what they call "Happy Hour", and like Ben said, I think it's every Friday, (Not sure myself), but you can send and receive private msgs without being a premium member.
It's usually identified when it's open at the top of the page when you first log into IHub, during that period.
It's neat, although I don't use it much. Someone did use it to contact me without going on the msg bd itself.
Regards, Gy