This question needs to be directed to an RAF recruiter.
Yes but only with the same gender
Not intentionally unless they are partners (as in a couple) or if they have to in communal showers at a gym, school, etc. But generally speaking - no.
Get clean.
you just ask her
Nowadays, women do not feel so constrained by gender roles. Traditionally , many countries had sex-segregated dancing, and some tradtional dances still are all men or all women.