For me the primary gotcha will be the Flag button's closeness to the Edit button. Fortunately Flag requires a confirmation. I expect that I will probably be using Edit a lot more than Flag.
I understand why Flag is where it is: everyone with more than a small reputation will have access to the Flag button for every post, but the other buttons appear much more selectively for most people. But understanding doesn't mean that I don't find the positioning annoying ;-)
A principle that I use in the layout of button groups that have no "natural" order, is that the most commonly employed button should be at the top, and the second most commonly employed button should be at the bottom. Humans position faster if what they use frequently are at the beginning and ends of groupings, because positions in the middle of groupings require more mental checking (e.g., reading) that one is at the proper middle location.