I wouldn't try and find technical meaning or reason to this move. It's a reactive move due to international news. What you want to see is what levels hold (or don't) on said news weighted against the importance of the actual news.
I don't think it's the timing of the rates specifically that's the issue it's the matter of IF they'll actually raise rates - and what might come along before the point if/when they do.
With specific regards to timing, they've been jawboning that September area quite a few times now, so if they back off, it says something.
What do you mean with that? Markets are all fully correlated in one way or another. Events in Ukraine do affect US equity futures in one way or another, and so does the devaluation of the Chinese Renminbi. Of course there is meaning in every event whether domestic or international. The US economy is as affected by global demand and global events as is the Chinese, Japanese, German and every other market.
No disagreement with any of that. If you read closer I said technical meaning. As in - why x/y/z support didn't hold or other micro-technical facets based on major currency news. Meaning: news throws a wrench in the gears as usual.