OTWO: I think you are quite right about some Torah "laws" which are actually idealistic construction and were never practically applied, except perhaps in very limited circles and periods (the sabbatical year / Jubilee system in Leviticus comes to mind). However I don't think this applies to legislations such as Exodus 22:16/17 which make perfect sense in an ancient (even pre-exilic) setting. The problem here (as in most cases where ancient laws scandalise modern readers) is simply that moral standards have changed along with social, economic, political situations. From the perspective of civil law (priestly legislations are different) women are viewed as quasi-property (belonging to their father, bridegroom, husband), as the Tenth Commandment nicely illustrates ("you shall not covet your neighbor's house; you shall not covet your neighbor's wife, or male or female slave, or ox, or donkey, or anything that belongs to your neighbor"). Hence engagement / marriage is a transaction between a prospective "buyer" (the bridegroom) and a seller (the father); sexual relationship before marriage cancels the transaction if the girl is already engaged to someone else (it is aggravated theft, just as adultery is), and diminishes its potential "market value" if she is not (on the importance of virginity, cf. Deuteronomy 22:13ff about the "evidence of virginity," which is still reflected in popular traditions in some Muslim countries for instance); it implies financial damage.
This is only a "problem" for those who assume that moral standards are universal and intemporal (and now we have them 100 % "right," of course!) and believe that the Bible as "God's book" should reflect such (which is certainly not the case of all "believers": faith is not incompatible with a sense of history in principle).