I thought about making some suggestions for the OP, but really, it's impossible to know where to start...
I'd 'cut some slack' over not knowing where Lambourne was, if it seemed that he had looked at the plates for Biggin and knew there was only one precision approach, or if he had read up on the services he might get OCAS, or if he had posted asking for some help without making a criticism of it.
Clunkdriver, have you any idea how long your slot delays would be into UK airports if the ATC service wasn't the very best? Have you any idea how many incidents occur in UK airspace specifically involving N registered business jets, whose crews have not briefed properly on the procedures?
And have you any idea how busy ATC positions like Thames can get? RTF loading is no indicator at all of workload. A controller might have fifteen aircraft on and be doing nothing, or have three on, and be shovelling like mad!