March 15, 1987

LEAD: AS soon as Sugar Ray Leonard hopped into the ring to shadow-box, his thighs appeared to be thicker and stronger than in earlier years. ''His body is different, he's bigger all over,'' one of his trainers, Angelo Dundee, was saying. ''He's a middleweight now, he'll weigh 158, but he's still smooth.

LEAD: THREE Federal administrative judges opened a hearing last week to consider the adequacy of a Long Island Lighting Company emergency evacuation plan for its Shoreham plant. But as the formal proceeding began, state and Suffolk County officials already seem to be looking ahead to Federal court fights, where they say the

LEAD: THE chemistry laboratory overflows with test tubes, encyclopedias and dusty stacks of turn-of-the-century trade magazines. In the crowded stockroom are exotica such as rare walnuts and rhinoceros tusks, and in the machine shop an obsolete grinder still churns and whirs - a symbol of Thomas Alva Edison's endless energy.

LEAD: Merger Game: Still Playing

LEAD: WATCHING foreign affairs is sometimes like watching a magician; the eye is drawn to the hand performing the dramatic flourishes, leaving the other hand - the one doing the important job - unnoticed. So it seemed last week as the