How many of those are theft or violence with victims, and how many of those are more like drug/alcohol infractions, or "disorderly conduct" caused by untreated mental health problems?

Afaik, there is more violence too. Yes, often caused by untreated mental health problems. Also more suicides. Combat situation tends to make mental health problems bigger in pretty much any aspect. It is not exactly easy or healthy situation to be in.

Veterans also face negative stereotypes which does not help anything either. Pro veteran groups tend to talk about all those openly, as they want to get more help to veterans before it all happens.

What are the negative stereotypes of ex service personnel?

I wouldn't exactly say I have my thumb on the pulse of Australia, but I don't seem to observe a negative stereotype for ex service personnel here.

I have personally seen prospects designed to combat negative stereotypes of veterans in American government office (employment office - don't recall exact name). The primary goal seemed to be to make employers more likely to hire them.