BRE is not really an alternative as most Hamburgers - especially from the north - would not like to travel the way through their tunnel and then to Bremen - many traffic jams.
BLL is no alternative, as it is to far away, even as Rostock which is more than 200 km away from Hamburg. Maybe Parchim or Jagel, if they open an airport there, but I donīt believe. So either FR buys LBC, finds an investor or they loose at least half of their potential in this region to Air Berlin, Easyjet and Germanwings at Hamburg International.