Yes this is possible, you need to look into Batch Processing. See Advanced > Document Processing > Batch Processing... where you can create a custom sequence to crop, preflight save to source folder etc.
Is there any way you put all of the batch processing and preflight into one Droplet that can sit on numerous desktops?
Plus I have ran a batch process and it has converted all the original hi res files to low res as well as saving a copy to the output folder. Is there anyway of retaining the original file?