UPDATE 3-Iran, powers explore nuclear compromises, Israel alarmed

* Ministers revise travel plans as deadline nears * Israel says possible deal is even worse than feared * Officials say Iran may be flexible on centrifuges (Adds senior U.S. official, Chinese statement, Iranian official) By Louis Charbonneau, John Irish and Parisa Hafezi LAUSANNE, Switzerland, March 29 (Reuters) - Iran and six world powers tried to break an impasse in nuclear negotiations on ...