You do know of the zoom tool in Photoshop, don't you? The only thing that could influence the maximum resolution of images in Photoshop is your RAM. Nog being able to save big jpgs could also be a RAM issue. Sometimes Photoshop says you are trying to save an image 'save for web' is not intented to, but still lets you try. 'Saving as...' and choosing jpg takes care of that. Maybe an image of your not-right looking hair could help for that part of your question.