Hong Kong is extremely safe for visitors, both male and female. As you go further north in Kowloon and into the New Territories, the crime rate increases, but criminals would still rather target locals than visitors. However, it's unwise to flash valuables and you should remain alert at all times.
Despite the 1991 removal of criminal penalties for homosexual acts between those over 18 years of age, people remain fairly conservative about homosexuality, and circumspection on the street is advisable.