1. The Camera is it's own device, however in this case it is slaved to the Host. So to access it you would either need to connect directly (with a cable) or get to it through the Host. Individuals do this to provide the low defense device with the defense of the host. Runners do this as well, by slaving their devices (smart links, cybereyes, etc) to their decker's cyberdeck, for better protection.
2. As scythe knight says.
3. As Scytheknight says. it's a 50 nuyen subscription that I tack on at middle lifestyle for free.
4. Virtual Machine gives you two slots, taking up one, so it effectively raises the programs you can run that aren't Virtual machine by 1.
If you normally run 3, you can run 4, not counting Virtual Machine.