MIAMI GARDENS, Fla. - When the request arrived in an e-mail last fall, Scott Fujita replied immediately and without reservation. A friend had asked him his opinion. He answered. That was how Fujita looked at it. The swiftness and certitude of Fujita’s reply stunned Dave Zirin, the friend who sent the e-mail. Zirin had not made a typical request, not for an NFL linebacker. He was looking for a professional athlete to lend his name to the National Equality March, a rally in Washington for gay rights.