Based off of the information Boocoodinkydow gave, I personally wouldn't change anything at first. It sounds as though the ed suffers from the lack of "go" compared to the hemi which is why the listed tow ratings are less. With that being said, the tires, rotors, brakes, suspension, & frame are the same as the hemi. Stopping the load should be no problem at all. The trailer should have brakes as well so that will assist you in stopping.
Now if you are drag racing a hemi up a wicked grade, you will most likely loose.....but who actually cares about that. I too have read about guys towing ridiculous amounts of weight and it sounds like the ecodiesel holds its own. However, I wouldn't go extreme often as the weak point will inevitably surface much sooner than expected. Based on what you want to tow, don't think you are in the ridiculous category. Heck you aren't far from its rated capacity.