Stock futures point to a lower open as crude oil tumbles and the Bank of Japan's quarterly manufacturing survey missed expectations; Dow -0.6%, S&P and Nasdaq -0.7%.Futures initially trimmed losses after non-farm payrolls showed employers added more jobs than expected in March, a sign of economic resilience that could allow the Fed to gradually raise rates this year.In Asia, Japan's Nikkei closed -3.5% while China's Shanghai Composite ended +0.2%; European markets are sharply lower, with Germany's DAX -2.8%, France's CAC -2.7% and U.K.'s FTSE -1.3%.U.S. crude oil -4% at $36.80/bbl on increased skepticism that a potential deal to freeze crude production can help clear the global glut.