need to be able to do some minor editing on some of my pictures (rotate by a few degrees, crop, color adjustment...) that apparently are not possible in iPhoto.
These are possible in iPhoto.
This library has a number of low-res BMP screenshots (some are 16-color),
Not a supported format.
are the photos in the Aperture library accessible through the OS in the same way iPhoto's library is?
Yes, if you a: check the option to Share Previews with iLife in the Preferences, and b: generate Previews. Note that it's the previews that are shared, and pretty much in all the ways that the iPhoto Library is shared.
Hrm. So it would seem that I could do in iPhoto what I thought it couldn't - didn't realize that... already used the straighten option to 'save' a couple otherwise marginal shots.
I ended up shifting all the BMPs and GIFs out of iPhoto back into a separate set of folders as it seems those should just be treated as files and not images.
I'll have to take a few steps back and take a good look at which direction I want to go. Thanks for the input.
TD: In the end, I ended up moving all the content that is not mine back into a hierarchical folder structure, leaving enough pictures to be distributed across four iPhoto libraries (for ease of DVD backup).
I'll eventually track down all the BMPs I still have and get them converted to JPG or PNG as appropriate.
I still have Aperture but have yet to make use of it (and I feel silly for pouncing on a "deal" when the price was temporarily lowered by $20). I just now tried the link that was suggested by Chris above only to find it dead.