 Which European leader would not want to swap places with Shell boss Peter Voser? He has just doubled the company's profits in the third quarter, amassed $30bn (?18.7bn) of cash over the last nine months and is now buying back shares at the rate of $800m every three months for want of anything better to do with the money. Voser has the advantage of having everything to gain from higher energy prices. The social and political fallout from rising fuel poverty and mutinous motorists rarely touches the parallel universe that is Shell Centre in London.  are there any Shell-shaped worries, then? Well, one of them - in 