I live just down the road from Biggin Hill and was talking to one of the managers at EBACE in May, and she said that they were indeed hiring out the hangar for functions, filming and anything that would make use of the space.
It would be a shame, as it is an impressive facility… But I did wonder if there was sufficient demand at Biggin Hill for a facility of that size and specification… On the FBO side… I don't know anything about the MRO.