By William Schomberg LONDON (Reuters) -Britain’s new finance minister Nadhim Zahawi pledged on Wednesday to rebuild and grow the struggling economy and said he would look at all policy options, including possible tax cuts. Zahawi, who took over the Treasury on Tuesday after the resignation of Rishi Sunak in protest against embattled Prime Minister Boris Johnson, said “nothing is off the table”. But the former education minister also faced questions about whether he would even have a chance to steer the economy out of its slowdown, given Johnson’s weakening grip on power. Among other government…