1) This could be a factor. I don't develop for OS X but it could be relevant to some (Although, personally, I feel there's too big of an obsession about "look and feel" from mac users).
2) This is barely relevant, imo. MOC does a great job and code generators have always been a good thing if you know what they generate and are one way only.
3) This could be a factor although I don't usually see a problem with dynamic linking.
for Qt, there's PyQt (I've used it and it's great) and PySide (no idea).
I used WxWidgets a couple of years ago and while it was easy to learn, it was nowhere near Qt in terms of features and documentation. Still, I hope it does well. I've seen plenty of nice programs using it.