Facebook is included in the unlimited social networking, therefore you don't need to connect to a Wi-Fi network to use the Facebook application. And I will specify that it's the Facebook app, you will not be able to access Facebook trough your Browser unless you are connected to a Wi-Fi.
As for updating your BBM, you just have to plug your phone into your computer and update through your Desktop Manager. If not, you can always use Blackberry App World directly from your device.
