Just on airlines. Edinburgh and Glasgow airports are fine to fly to. I don't know Edinburgh airport surroundings well but thereis a tram service which takes bikes and goes into the city centre. Glasgow you can assemble the bike and cycle out the airport with several cycle routes nearby and cycle friendly roads.

As it happens I went past the airport yesterday over a new cycle/pedestrian bridge built as part of a bike route from the airport. You could land at Glasgow and have an easy connection to NCN7 heading north.