It helps you better understand your boundaries and expectations from a partner. Conflicts often arise from a mismatch in core attitudes (e.g., one values "intimacy" while the other values "functionality").
Yes. They are influenced by life experience, new relationships, therapy, and even changes in cultural environment. Sexual attitudes are a dynamic structure that can transform as you grow.
Not necessarily. A person can have an attitude focused on "intimacy" (sex only through love) but still be very open to experimentation within those stable and trusting relationships.