"are 2 men a week being murdered by their female partners or ex partners?"
No, in the 2008/2009 figures 31 men were killed by an partner or ex partner compared to 101 women.
So for every four victims killed by DV one will be a man.
"Is this just for female partner violence or does it include male partner and/ or father/ stepfather violence"
This is all by the BCS definition of "Domestic Violence" which is "Any incident or threatening behaviour, violence or abuse (psychological, physical, sexual, financial or emotional) between adults who are or have been intimate partners or are family members, regardless of gender or sexual orientation."
And the BCS shows that women are also slightly more likely to be the victims of "family abuse" rather than "partner abuse".
So if you want to discount that sort of violence and leave it just as "partners" then the proportion of men to women victims of DV will actually increase rather than decrease as you seem to suggest.
"I would also question if men really are less likely to report - if you take into consideration that the average woman will be the victim of an attack more than 30 times before she report it, hwo many attacks will men suffer before they report it?"
Well again this is from the BCS women are more likely to tell someone (89% vs 59%) and in particular more likely to tell friends (66% vs. 44%) or the police (20% vs 10%) than men are.
So according to the figures men are twice as likely as women (41% vs. 19%) to tell no one about DV before they end up in the BCS.
The the figures should tell you that the numbers of male victims of DV that we hear about are the tip of the ice berg.
I can also back that up personally, that male friend that I knew bluntly said that they didn't tell anyone for years because they felt that it wouldn't be taken seriously.
DV is never going to be comprehensively tackled until we stop and take into view the whole picture of what's going on and stop clinging to stereotypes of what DV is, who suffers and who perpetrates it.
The situation with male victims of DV is where we were decades ago with female victims, it's just not taken seriously and dismissed as irrelevant or even "funny".