Just wanted to second this request! I'm new to Tropy so I may have my terminology wrong, but if an "item" is a set of photos one has merged to create a document, then this definitely would need to be independent of that (ideally, I guess, both "rotate all in item" and a command/ctrl-select any set of photos). For me at least, to even be able to decide which photos to merge to form a document I'll have to rotate them once I've imported them.
Although, on second thought, I've just noticed that the space bar view doesn't seem to change after rotating the images, so perhaps it's just easier to complete this step in another program prior to importing. On a Mac, Preview handles this pretty neatly.
Also, sort of related, would love a view that combines the project and item views, sort of, so that one could see thumbnails of the photos in the project on one side when one is in the item view.