Concentration camp (KZ) sounds about right. The term for places like Dachau and Auschwitz is Vernichtungslager (extermination camp). A concentration camp is not set up for industrial mass-murder of its prisoners.
In modern English the distinction is not consistently made. Sometimes you see extermination camps and concentration camps talked about, but other times you see both talked about just as 'concentration camps'.
I certainly agree. Concentration camp is an umbrella term, both in German and English. However, if we're talking about the exact type of camps, it makes sense use the proper words and inform readers of the distinction. It's only fair to the victims to use appropriate language and not play down the severity of their situation.
Yes, I agree. To be clear, I do prefer using the term "concentration camps" to refer to what the US did to the Japanese, but I understand that others object to that and find their objections fairly reasonable.
I wouldn't necessarily argue the use of "concentration camps," but as I said in this thread, my grandparents and many of their family and friends were interned and they all use "internment camp" as the preferred nomenclature. They have generally avoided the use of "concentration camp."