For more than two decades, Keith Kelly was the feared-and-revered media reporter of The New York Post. Now, at 71, he’s three years into a decidedly different gig: editing a group of scrappy, hyperlocal Big Apple weeklies owned by Straus Media, including West Side Spirit , Chelsea News and Our Town Downtown . “It is not as different or as difficult as one might think,” he says of the transition. “I knew who the good guys and the bad guys were, where the figurative bodies were buried. Now I’m covering the neighborhoods of Manhattan the same way.” Kelly, who got his start a half-century ago at a weekly (“I’m right back where I started”), likes that his titles still make their money the old-fashioned way — from advertisements in print. That means he operates at a remove from today’s internet-oriented deadline pressure. “We’re not under the gun that way,” he explains.…