The phrase is "at least partly responsible", which makes it worse. "drunk" is also open to interpretation; other studies have used "has been drinking" with similar results.

[other people may think] that a woman who gets herself paralytic, on her own, in the company of people she doesn't know is asking for trouble

Would a man in the same situation (change the genders and/or sexualities of the other people as necessary) be considered to have been asking for trouble? Society's attitude to excessive drinking varies depending on who is doing the drinking.

I'm not sure how one can draw a distinction between "asking for trouble" and "reducing the blame on the rapist" - if the victim is considered "partly responsible" (in any sense) then it's not logically possible to consider the rapist "totally responsible".

I'm strongly of the opinion that, whatever point you want to prove, statistics need to be fair, accurate, as informative as possible, and understood as much as possible.

Well, yes, obviously. I believe at least most of the questions you asked *have* been answered by government and private research.
For domestic violence, Walby and Allen (2004)
http://www.homeoffice.gov.uk/rds/pdfs04/hors276.pdf
For rape, Kelly, Lovett and Regan (2005)
http://www.homeoffice.gov.uk/rds/pdfs05/hors293.pdf

They're both quite long papers, but they answer quite a few of your questions better than I'll be able to. There's a lot more on the Home Office site but those seem to be good generally.

Did the person who slapped the partner who apologised immediately genuinely mean it, or is that just an excuse for further acts later?

It's not an either-or question, of course. Very often both are true.

Any making serious allegations like that against people who have a disagreement with really does undermine the case.

Apologies. I didn't think you actually thought that, and didn't mean to imply it - I only intended to point out that the wording you were using was coming far too close to implying you did think that. Text is an appalling medium for this sort of discussion, of course.

but one miscarriage of justice isn't the same as a pattern of attitudes.

No, but the pattern of attitudes makes court decisions like that more likely. (Two, incidentally, not one; the articles were about separate incidents) It's not hard to dig out similar examples from further back.

case of the American man

Absolutely unacceptable, of course. Though, if you want to include American cases too, have a look at this very recent Supreme Court decision
http://www.washingtonpost.com/wp-dyn/content/article/2008/06/25/AR2008062502614.html?hpid=topnews
and this case at State level
http://www.cbsnews.com/stories/2008/06/11/national/main4172878.shtml?source=RSSattr=U.S._4172878
Both are about domestic violence ending in murder.

Still, it's fair to say that domestic violence against anyone is taken considerably less seriously than it deserves in general, but this is a problem that disproportionately affects women as they are more likely to be victims of it, and massively more likely to be seriously injured or murdered.