plainmaker: Australia Asia Airlines was set up so services to Taiwan would not offend China. The IATA code for the entity was IM, the ICAO code was AAU, the call sign was Austasia. For all intentional purposes it was a new airline with both a B747SP and a B763. KLM did something similar with KLM Asia as a Taiwan registered subsidiary of KLM Royal Dutch Airlines.
As far a slots are concerned at LHR you can do what you like. I would be surprised if you were not aware QF has leased a pair of slots to BA.