score:6
Yes for the Austro-Prussian War, But no more or less than any other force of the period.
The rounding up an executing of civilian hostages as reprisal for franc-tirers did not, so far as I know, occur in the Austro-Prussian war. I don't know much on the Prussian-Dutch war, so will refrain from comment there. Looting of towns and some "outrages" against women were noted, but from my impression were not widespread. While the rape was generally frowned on, both that and the looting were more-or-less seen as "the cost of doing business" in armies operating in enemy territory until very recently. So while they would absolutely count as war crimes today, the Prussian army wouldn't have been thought of as uncommonly violent towards civilians at the time.
I would guess that the short duration of the war limited opportunity as well as the "bitterness" between enemies. Plus when civilians (or enemy soldiers for that matter) speak your language it's harder to treat them as impersonal "things" which in turn tamps down on violents towards noncombatants. The obvious exception of course being a Civil War, but even there "looks like me, speaks my language" tends to make for more "civilized" wars then ones that fracture on ethnic/religious lines.
As a note on franc-tierurs even modern-day armies are allowed to shoot them out of hand (insofar as they're not covered under the Geneva Convention) and "Execute anyone caught out of uniform bearing arms against us, and take hostages to stop it happening" is a commonality in pre-1900s warfare. So while the Prussian actions against them/local populations as reprisals in the Franco-Prussian war and WWI were vilified by the French and their allies, they weren't any different than, say, what French forces did in Spain during the Napoleonic Wars, or British troops in India during their various wars to conquer the Raj.