Paranoia is frequently a welcome presence at major client presentations for Katharine Paine, founder and CEO of The Delahaye Group Inc. In the past, twinges of seemingly unfounded worry have caused Paine to personally attend sales pitches where she learned of serious problems with the way her firm was doing business, she says. The head of the 50-person Portsmouth, New Hampshire, marketing evaluation research firm traces her paranoia style to childhood days spent pretending to be an Indian tracking quarry through the forest. When she makes mental checklists about things that could go wrong or opportunities that could be missed