Legal proceedings no TV licence

could be wrong on this but I think you need a licence for a cctv system too even if its only used for security purposes.
 
I'm not sure that's correct: surely it depends on the type of monitor used? If it's a regular TV (i.e. display with tuner) it would need a license, but don't some CCTV systems use simple monitors with no tuner (i.e. bit like a monitor on a PC)? if so, I don't think it would need a license, as such monitors are not capable of receiving broadcast signals.
 
what about a walkie talkie ?

Exempt as far as I know. I think in practice they will exempt anything they know not to be a TV. They probably only get stubborn about the roof aerials and the like either through officiousness or because they suspect the owners do actually have a TV.