Not at all. Prior to WWI, the US was aggressively and intentionally cleaning European interests out of the Western hemisphere. It was in frequent wars, often with one European power or another. It just didn't distract itself too much with squabbles between European powers over matters outside its claimed dominion.
Establishing a hemispheric sphere of influence was no act of neutrality.
Yes, most of the time from the founding until the First World War.
> and openness?
Not sure what sense of "openness" is relevant here.