Derrick Rose spent 16 years making NBA defenses look helpless with his speed and explosiveness. Now, less than two years into retirement, the former MVP has found a very different way to make an impression: through flowers. That’s quite a symbolism. Rose’s new business, Rose’s Flower Shop, has already stepped onto a bigger platform. And LeBron James just gave that second act a spotlight. On his Instagram stories, the 76ers superstar shared a pos…