I grew up in one of those "extremely restrictive faiths" that was mentioned. They do feel that sex is for procreation, not dirty really, but very much so had a particular purpose. If you do a quick search in google you can find those places in the bible that mention sex, and marriage, and what it actually says. You don't need to pick up a bible anymore. People have done all the research for us.
As far as what ManOfFaith believes, it's not my place to pass judgement on how he partakes in BDSM or how he incorporates it into his marriage with his wife. What I see this soul seeking is a way to partake in those things he and his wife find enjoyable, and yet remain true to what they have come to believe in.
Values, beliefs and faith are all a very tricky thing to nail down. If you were to look at each of them, ask what was was the most dificult to change and most cherrished you get values. Values are derived from beliefs, and beliefs can be changed more easily than values. If your beliefs are changed in time values (if your beliefs remain constant) will follow the beliefs. That is assuming you maintain faith in your beliefs.
Faith on the other hand is simply putting your ideas, and your hopes in something you can't see nor can you touch it. Faith is just that, faith.
This all of course is just my opinion, and just like faith or beliefs varies from person to person.
V/R
ID