Sexual Trauma

Why do individuals involved in sexual trauma develop kinks directly related to their trauma?
How can different kinks be non-sexual?
How can be BDSM be used to cope with mental traumas?
How and why do individuals become involved in BDSM?
What are the effects on the psyche of relationships with power dynamics?
How is BDMS perceived mainstream?
Is there an age group or specific trauma that causes individuals to develop kinks related to their traumas?