Such routes as Nice and Marseille, are they needed? Surely these are just leasure routes and anyone connecting will just go through Cdg? You have low cost carriers like Germanwings and Vueling, why? Surely if your flying from Bilbao, A Coruna IAG would rather you go through their Madrid hub?
I must admit I was a bit surprised to see routes like LHR - Alicante on BA being launched, but I wouldn't be surprised if BA can make these routes work, especially at certain times where demand for 'business routes' is weaker.
Germanwings (part of the Lufthansa Group) and Vueling (46% owned by IAG) are both at LHR for similar reasons. LH uses Germanwings as a lower-cost operator on certain LHR-Germany routes and expect to see a lot more of them as Germanwings will be taking over ALL of LH's non-hub routes (LHR-HAM/DUS/STR e.t.c) out of LHR. I suspect that IAG (well, IB) is looking at similar strategy with Vueling (although IB already has Iberia Express).