don't really get what your last post means...but here's a shot:
Adobe Camera RAW (ACR) adjusts a RAW file without damaging or writing new info into the RAW file. What you see as the modified file is actually just a bunch of settings that ACR remembers to attach to that RAW file when it opens the RAW file. It remembers these settings by saving them in a small side-car file that has a similar name as the original RAW file. There is no new RAW file produced.
These adjustments to the brightness, etc. will to some extent affect the quality of the image produced. By making an image brighter or darker, increasing contrast, etc., we will cause some damage to the produced image. Of course, if the adjustments are small, the "damage" done would not be noticeable. But if we change the settings drastically, the "damage" done would be pretty noticeable. This is the same whether the program we use is ACR, DPP, Capture One, etc. But this "damage" would only surface in the output file processed by the RAW conversion program, and the original RAW file would be untouched.
Hope that is clearer
