Fairdealfrank - 100% agree on your last point. LHR expansion is long overdue.
As for BA, personally I feel that in the long run R3 would be good for BA. The influx of new competition would force them to deal with issues that they have so far been reluctant to address. In particularly the high unit costs in short haul, and the terribly inefficient LHR ground operation (the two are related of course).