Yes, you can with the online fax service right now. Ringcentral offers the service with a 30 days trial period.
Yeap.
You do not need any land line at all in order to own and use a cell phone.
No you don't need a separate line for fax machine,you can use a multi jack and use both telephone and fax on the same jack and programme the line in such a way that if you are not picking the phone...
yes