By Mary Jane Credeu Bloomberg April 5, 2007 Starbucks Corp. Chairman Howard Schultz says he can preserve the chain's coffee-house nature even as he adds seven new stores a day. ``This is really hard to do,'' Schultz said in an interview at the Seattle headquarters of the world's largest coffee-shop chain. ``And because very few people have done it before, they're out there waiting for us to fall.'' Schultz's concern about damaging what he calls ``the intimacy of the experience'' at Starbucks surfaced in February, when a memo he wrote was published in newspapers and on the Web. In it, he urged executives to re-think decisions such as using automatic espresso machines instead of having baristas draw shots by hand. He said such moves could lead to a ``watering down'' and ``commoditization.'' ``He's rightfully questioning things like whether the restrooms are clean, and how long the lines are,'' said Reed Bender, who helps...