I know of NJE pilots in all the above mentioned bases. If they are there I guess its possible more pax can live there..
If you are Norwegian or Swedish and work for an international company, regardless of wich(NJE, Global Jet... internet chip international) and in the contract you must pay incometax to the country of your companys HQ, in NJE`s case Portugal and UK(social security), both mentioned countrys have a bilateral tax argeement that prevents dual taxation. Just contact your local tax agent and get the facts instead of waisting time here speculating.
cheers.