I could rant for hours about Adobe software, and I'm not even a programmer.
Speaking of Adobe: I was editing some Halloween photos tonight for a friend, and I ran into my problem 1 (see original post) with Photoshop Elements, i.e. multiple files didn't all open in Photoshop when told to do so in the Finder. So unless Photoshop Elements suffers from the same bug as Preview (maybe due to an underlying change in OS X?), this could be a Finder bug rather than a Preview bug.