Can I have some crowd-sourcing help here about gun-safety in the home?

Police chief get a gunI’m in a very polite discussion with someone about gun safety.  I’ve managed to use data to convince this person that America is not home to exceptional gun rampages, that they occur in other countries, and that those denied guns go on rampages with other things.  I’ve also shown that gun control laws in England have seen increased violent crime, while gun control laws in Australia did nothing to affect gun crime statistics, which were dropping anyway.  The next line of discussion is whether guns in the home are so dangerous to family members that they have no merit for self-defense purposes.

The obvious argument is that you cannot insulate yourself entirely from risk.  If you banish guns, you get crime; you have guns, you get self-defense with an increased risk to family.  But what I’m wondering about is the credibility of the data she politely offered.  Do any of you know whether the following is correct and, if it’s not, do you know what accurate information is about gun-safety in the home.  (And I wonder, off hand, whether it’s greater or less than pool safety, or falling out of window safety, or eating poison safety, or getting beaten to death safety, etc.).

This, from a “firearms tutorial” out of Utah:

The issue of “home defense” or protection against intruders or assailants may well be misrepresented. A study of 626 shootings in or around a residence in three U.S. cities revealed that, for every time a gun in the home was used in a self-defense or legally justifiable shooting, there were four unintentional shootings, seven criminal assaults or homicides, and 11 attempted or completed suicides (Kellermann et al, 1998). Over 50% of all households in the U.S. admit to having firearms (Nelson et al, 1987). In another study, regardless of storage practice, type of gun, or number of firearms in the home, having a gun in the home was associated with an increased risk of firearm homicide and suicide in the home (Dahlberg, Ikeda and Kresnow, 2004). Persons who own a gun and who engage in abuse of intimate partners such as a spouse are more likely to use a gun to threaten their intimate partner. (Rothman et al, 2005). Individuals in possession of a gun at the time of an assault are 4.46 times more likely to be shot in the assault than persons not in possession (Branas et al, 2009). It would appear that, rather than being used for defense, most of these weapons inflict injuries on the owners and their families.

and this, from the Law Center to Prevent Gun Violence:

Of the 13,636 Americans who were murdered in 2009, only 215 were killed by firearms (165 by handguns) in homicides by private citizens that law enforcement determined were justifiable.