Murphy, I like your idea, and I agree with you on many of the points you made.
Even though I think this would make an excelent mutator, I dont think it should be added into RO for a few reasons, some that have allready been mensioned. (Though I felt a few of the points against the idea were kinda silly, almost like they didn't read your posts.)
Personally, even though this idea has a good chance of creating the type of sway and weapon control your looking for, I think the way the player would have to control those movements would be akward and I dont believe many players would want to tolerate it. Realism wize this idea has merit, but gameplay wize I see a few problems.
Mostly I imagine having to slowly move my mouse up and then jerk it down as I fire the gun, and then having to slowly move my mouse up again and repeat the process many times during a whole game. I think my arm would get tired after my first few kills.
Then there is also the possibility of it going bad if it isn't coded properly, though I doubt that TW would have that problem.
I think more appropriate methods to improving weapon sway (and to some degree, recoil) would be additions such as having to re-aim after changing stance or reloading, and having greater amounts of sway while supressed.
Even though I dont think it should be included, your idea is unique and imagineitive, and it shows excelent creativity. I think it would turn out to be a fabiluous mutator. Keep those ideas coming, I look forward to reading more from you.