By Jed Horowitz NEW YORK (Reuters) - Wells Fargo & Co is slashing an approved list of money managers and investment vehicles that its stockbrokers market to the firm's wealthy clients, a change of direction that has rattled the third-largest U.S. brokerage network. Executives said the clampdown protects clients from exposure to a plethora of investment models that have received little oversight. It will also reduce the firm's risk at a time when litigation and compliance costs are rising industry wide. ...