<<Farnborough (EGLF), is outside CAS, for God's sake. >>
And, for God's sake, Farnborough is a busy airfield and has a licenced ATC unit which includes very busy radar sectors. It's also very close to several other airfields and Class A airspace. If you think you would be safe flying in and out of Farnborough on a "DIY basis" then I think you need to spend an hour or two at Farnborough Radar one day. You might be surprised!