By the very nature of digital capture, most, if not all, digital images need some degree of refinements to correct the artifacts created by digital capture. A digital image, for instance, cannot at today's technology able to cleanly capture "tack sharpness" due to the image sensor's inability to clearly separate edges of an image. This needs to be further enhanced by software to increase the contrast at the edges, either within the camera or outside using the PC.
Personally,I feel there shld be no hard and fast rules. There are some purists who will insist there shld not be any manipulation,not even cropping of the image. But photography, to me, is after all an art. It is expression of how we see the world and how we want to communicate that expression to others.
Do what you think "feels" right. Don't be limited by what others think. If there are new tools available, try them out and see if they can help you "express" yourselves. It is your art after all. Learn all you can from the experts and then develop a style of your own. Along the way, don't forget to have fun. Best of luck!