Your first link is to the American Psychological Association, and only a 9very) brief abstract. I searched and did not find the paper anywhere that wasn't paywalled. So this doesn't really say anything. It said "evidence of impairment" at ridiculously low concentrations of 0.015% (15 mg/dl), but doesn't say anything about at what point they consider "significant", or how how impairment was measured. What was the methodology? Without that information this is meaningless. It says exactly nothing about the subject under discussion.
Your second link is just a straw-man. Quote:
[Of the five] States adopting 0.08% laws experienced 16% and 18% relative postlaw declines in the proportions of fatal crashes involving fatally injured drivers whose blood alcohol levels were 0.08% or higher and 0.15% or higher. CONCLUSIONS: It all states adopted 0.08% legal blood alcohol limits, at least 500 to 600 fewer fatal crashes would occur annually.
This says nothing about the effects of alcohol. I has to do with the effects of the law, and the behavior of people in states which passed those laws. While it might be reasonable to think there is some relationship between the two, that's not what the study shows. Further, the numbers given are of drivers who killed themselves, not of drivers who were endangering others. The whole point of the law was supposed to be about endangering others. I have zero respect for laws that try to protect me from myself.
Your third link:
There is no evidence of a threshold blood alcohol (BAC) below which impairment does not occur
Another straw-man. I don't dispute this, but it's irrelevant. The whole subject here was the point at which impairment is significant enough to endanger others. That is supposed to be the point of the law.
All of these are rather vague conclusions which skirt the real issue (which does not surprise me in the least... it is rather typical of "studies" that attempt to support a forgone conclusion).
My main point though is: even if these studies validly contradicted the ones I mentioned (they don't), that doesn't mean the ones I mentioned don't exist. Contradictory studies happen all the time. It doesn't prove me wrong, it just implies that there is controversy.