Britain's FTSE 100 index is seen opening up 8 points at 7,384 points on Tuesday, according to financial bookmakers. * BRITISH ELECTIONS: A host of candidates to replace Theresa May as British prime minister launched their campaigns on Monday promising to solve the turmoil of Brexit and taking shots at frontrunner Boris Johnson. * SHELL: Royal Dutch Shell on Monday shipped the long-awaited first cargo of liquefied natural gas from its massive Prelude floating