Turbo Tom
You've got it in one, it is NAS policy when entering a new market to go very aggressive on price, to get the name known and people to try Norwegian, research show that once people have tried Norwegian they tend to come back and fly again, that in turn allows them to gain pricing traction.
LN-KGL
I think the comparison with SWISS is valid : both operate new aircraft, the flip down IFE screens are the same, even show the same Mr Bean sketch's with SWISS (in economy) you get a free soft drink or tea/coffee and a small tart, with NAS you pay for those, but you get free Wifi, the Reccaro seats are the same. Leg room is equal, with only 186 seats on NAS rather than the standard 189 config.
I think there is little doubt that Norwegians rapid growth at LGW & elsewhere will have made Ryanair & others look again at service levels.
Will long haul work out of LGW? I have no idea, but comparison with eos & maxjet mean nothing and a lot has changed since Freddie Laker's days, time will tell...