Dan, since starting to use RAW+DPP I download into a folder called abcd.CR2 and save edited files to abcd.jpg. I don't see how you can lose the originals unless you are taking an option somewhere to do so that I have not seen. When you leave a folder it does give you options save 'all', don't save etc.; if you take the save & all, the .CR2 s include both the original and all edit instructions, just use reset buttons to return to original to start a different edit.

You can also still improve the .jpg a lot in the RGB pane, but more risk of introducing new colour casts. The (top) brightness slider in the RAW pane adjusts under/over exposure using the surplus material captured by the camera, whereas in the RGB pane it is by 'combing out' selected pixels as shown graphically in the 'levels' histogram. The shadows/highlight short cut in PSE or CS automates the 'levels' alterations. The Levels process can also be done taking R,G,B individually (to keep that rather lovely red-brown fringe on the black horse.)