The GA comment was probably more an indication of what the RAF has actually planned for. Other than being vigilant I don't really see how you can plan against terrorism, but you can plan against VFR fliers that are "temporarily unsure of their position". The majority of commercial traffic should after all be busy following the magenta line or similar.
I object to anybody wishing there were more terrorists to shoot.
Don't get me wrong, I don't wish for more terrorists, just for existing terrorists to be dealt with in a fair and efficient manner. 