Thanks Richard, that worked! The only thing that doesn't is cropping, which was my original hope - to batch crop a bunch of images to the same parameters. Having to be in edit mode restricts us to one image at a time, which seems very clunky. Having to be in edit mode at all seems clunky, for that matter. Thanks again for your response!
Edit: I have submitted the following to Apple Feedback. Everyone else, please feel free to use this template:
After more research, I have discovered that in order to Copy Adjustments, you have to first edit the original photo, then get out of Edit mode, then get back into Edit mode, then copy adjustments. Then you have to get into Edit Mode in the next image, then Paste Adjustments. Also, Copy Adjustments does not copy Crop information, which needs to be included. This seems like waaayyy too many steps to do a simple operation.
Here is my suggestion for fixing it. Allow multiple selected images without having to be in Edit Mode. Make Copy and Paste Adjustments (or at least Paste) available without having to be in Edit Mode:
1. Adjust original photo in Edit Mode. Copy Adjustments, INCLUDING CROP INFO *while in Edit Mode* That option is not available now
2. Click Done
3. Select one *or multiple* images to apply the adjustments to
4. Paste adjustments, all selected Photos are adjusted without having to do each one seperately.
This easily allows Batch Cropping or other Batch adjustments and largely increases the power of Photos.