Would it be fairly straightforward to at least add a preference to resolve file aliases?
I would say directory aliases are as at least as important in this respect (if not more so).
Please note, however, there are three types of "aliases" on the Mac.
1. An alias as created with the Mac GUI.
2. A soft link (e.g., as created with the Terminal command ln -s).
3. A hard link (e.g., as created with the Terminal command ln -s).
The hard link is actually already supported as it looks like a normal file. Support for the other two would be very very much appreciated as this would enable, for instance, a single directory structure for all your image files even when this is split across different media.
I don't know how hard it would be to implement "aliases" within PM though, and this may in fact be quite a big one...
Cheers,
Hayo