Boston Ballet will look very different this fall. That’s because 32 of the company’s 55 dancers will be new to the company. “Any time you have a big bunch of new dancers,” artistic director Mikko Nissinen said, “it changes the company’s chemistry.” To find his new hires, he held auditions in London, New York, and Boston. “I saw over 1,000 people in the process. They’re going to enhance the qualities I’m emphasizing onstage: more musicality; clean technique; simple, fresh presentation; and quality, quality, quality.”