The concept of Pikuach nefesh derives from the biblical verse Lev 18:5
"So you shall keep my precepts [commands given without reason], and my judgments, the one who does them, the man will live by them, I am Hashem"
So the commandments are to bring life not death. From that line we get the basis of the pikuach nefesh concept.
The mishnah elaborates with examples, putting out fires on sabbath to save people, etc. Importantly the concept of "uncertainty of life risk" is cultivated.
If one is uncertain if there is a life risk or not (in decided to break another commandment), he must assume it is a life risk and act.
The only instances where a torah command can not be violated to save a life have to do with denying G-d (bowing to other gods, etc).
pikuach nefesh - life risk, is discussed in many interesting examples in Talmud Bavli Tractate Yoma [83-84] (both sides of the pages)
A lot of interesting marital things can be found in Talmud Bavli tractate Ketubbot (sometimes spelled Ketubboth or Ketubbos [German Jews]) with 1 or 2 b's
Talmud Bavli Tractate Ketubbot [72a] - discusses how a woman who curses her husband's parents in his presence (some say in the childrens' presence) can be divorced without payment (they don't get what is written in their marriage contract). I can't find the authority who permits beating in this case. I think it's a machloket (disagreement without verdict) among the sages if beating is permissible or not in this instance.
For the concept that the court can have a husband beaten see Rashi on Leviticus 21 (though Rashi's justification is forcing a man to divorce an illegitimate wife)
For the idea that a beit din can compel a husband to divorce his wife, see Rambam's "Laws of Divorce" 2:20
Rashba's Teshuvot: 4, section 113 & 5, section, 264 & 7 section 477 make the case for Rabbis taking the side of women who are beaten regularly
There's more in Tractate Gittin but I gotta sleep, hope that helps