>>>If I was on benefit and could only afford terrestrial TV(BBC licence fee), unless I had a Freeview box, could I access those channels?
Since the digital changeover, it's impossible to receive
any terrestrial TV without either a Freeview box or a TV set with built-in Freeview. So every home in the country that has terrestrial TV gets all of these channels subscription-free:
http://www.freeview.co.uk/whats-on/channels
(Note that the top section there is for HD channels, which require an HD Freeview Box or TV set with a built-in Freeview HD receiver. It's everything BELOW that section which is available to ALL households with terrestrial TV).