I'm not trained in philosophy, so I'm sure any response I give will be sadly lacking from a formal standpoint. That, however, has never stopped me from shooting my mouth off before and it won't stop me this time.
Pornography->Patriarchy
I disagree strongly with the claims of Brison, at least as presented in your post. The idea that pornography of any kind is guiding the path of history seems ludicrous, and as reactionary in its way as the claims from the far Right that pornography is destroying our youth. The world is a complicated place with an unimaginable number of factors determining what its shape will be, and I'm automatically suspicious of anyone who tries to make a sweeping claim of causality. Every time someone claims to have found a simple answer to pretty much anything outside the realm of hard science (and often even in the realm of hard science) they turn out to be wrong. Just look at the economic events of the last decade for some very clear examples of people thinking that they had figured things out only to find that whoops, no, the world is more complicated than that.
Every one of us has had moments when we think "if only (I made more money, had a good relationship, studied something different in school, had learned skill X 10 years ago) were different, my life would be so much better." It's a very slippery slope for people with philosophical or moral agendas to map the ills of the world to things that they find offensive, and to convince themselves that if only X were gone the world would be better. That's a much more comforting way to look at things than to have to face the fact that the world is incredibly complicated, brutally unfair, and that change is a slow, arduous process.
On to the claims of moral defect.
First, as regards pornography
I don't think that the enjoyment of violent pornography is inherently bad, but we should all be aware that pornography can, and often is, created in an unethical manner. We all have a responsibility to know where our pornography is coming from, the circumstances under which it is made, and the circumstances of the performers. The idea that we live in a society in which some people refuse to eat industrially produced meat due to a desire for animals to not be abused, but would at the same time pay for and consume pornography produced in an unsafe, insane, or non-consensual manner is frankly unconscionable. If you care about the history of what you eat you should care equally about the history of what you feed your desires, as both can be equally poisonous.
Secondarily as regards pornography, people should be very careful to make sure they continue to recognize the line between fantasy and reality. This can easily become blurred, and it's very easy for people to start drawing moral equivalencies between the fiction produced by professionals for titillation and the realities of how people should be treated. It's a potentially dangerous path and everyone walking it should regularly stop and look down to make certain his or her feet are still on the road.
With regards to sexual relations
Violence is defined as "Behavior involving physical force intended to hurt, damage, or kill someone or something." (http://bit.ly/ldkFUN) While that would seem on the surface to apply to BDSM I would argue that it does not.
Modern, ethical BDSM is characterized as being Safe, Sane, and Consensual. If an act or relationship is SSC then I do not believe that it meets the burden of the definition of the word violence.
Consent: Consent is obviously key. Sex without consent is rape. It is unconscionable, and it is violent. No sex should ever happen without consent.
Sanity: A person could theoretically be able to consent to their own murder, but it would frankly not be sane. For sex to be sane both (all) participants must take into account the potential longterm effects of the acts, and must be prepared to support and care for their partners as necessary, preventing them from taking unreasonable steps.
Safety: Shit can get out of hand. A person who allows things to reach a point that they are not safe is being negligent, and is showing a lack of care for his or her partner(s). Safety requires that all participants be aware of the physical and emotional situation, and are prepared to change course or stop completely if danger looms.
So
If a person is with a consensual partner, participating in acts that both believe are not going to be damaging and which are not going to cause harm to their partner, and if participants are careful and aware and prepared to stop if something gets out of hand, then I don't believe the sex can be characterized as violent as it is not meant to cause harm or damage. If BDSM is not violent then does not fall under the categorization of moral defect.