If I have 16 employees and I figure that 1/2 of them might be on the phone at once (Not sure if this sounds high or low) and if I go with say Broadvoice, do I: A) Have to purchase Unlimited Business for each of the 8 lines that might be in use? B) If I want all phone calls to com eto one main number (IE our office number) can this be done? C)They also offer a service called "Bring Your Own Device" (BYOD) VoIP option that gives you an unprecedented opportunity to pick a phone number in any one of our 3,800 rate centers, have your device provisioned immediately, and start making calls within minutes. Is that the option I want? ps: also what about security to calls in and outbound.. any worries?