Petroleum News Alaska by Gary Park.  Japan’s largest importer of LNG has delivered a sharp jolt to the British Columbia government: Drop the idea of a tax on gas exports or put its LNG dreams in danger.  Tepco, Tokyo Electric Power Co., also prodded the government to resolve the concerns raised by First Nations about the construction of pipelines from northeastern British Columbia gas fields to coastal liquefaction terminals.  A company spokeswoman said uncertainty hanging over the LNG projects, including taxation on Greenfield operations, could slow or stop plans.  Tepco also said that First Nations issues could have a “material adverse effect on pipeline construction.” … Global energy consultant Wood Mackenzie said in a new report that although Canada can rightly claim political stability as an advantage over some of its LNG rivals, that edge could be offset by high construction costs and possible court challenges from First Nations.