I've got a few questions:
1. Is there a way to move the starting point of e.g. a marquee selection while still in the process of selecting? In Photoshop, this works by starting to drag, holding Space and continuing to drag. I use this all the time. (It works for the built-in OS X screenshot facility as well, btw.)
2. When the prefs window is the topmost one and I try to close it using Cmd+W, I always end up closing the document window behind it instead. Is there a reason for this awkward behaviour?
3. [ and ] don't change the brush size for me, although they're set as shortcuts in the prefs window. I assume this is a bug? (I am using a German keyboard, where square brackets are entered through Optn+5 and Optn+6.)