Sure, from a distance the title characters of “The Lyons,” the Nicky Silver play that opened on Monday night at the Cort Theater in a production starring the fabulous Linda Lavin, are hilarious as they kick the ego out of one another. But look at them close — no, closer — and you’re likely to find an intimate mirror of your own frightened self. Welcome to Broadway at last, Mr. Silver. And might I add that that this cozy-but-nasty family portrait is just the right vehicle to bring you here?