“Wellfleet Harbor Actors Theater has made a name for itself as a presenter of dark, edgy, groundbreaking theater.” This season, after losing half a million dollars last year and slashing its budget, the company’s offerings look different — which is to say, frothier and more mainstream. “But in moving from dark drama toward light farce, from the fringe toward the center, WHAT is hardly alone this year among New England’s summer theaters.”