everybody wants a nice comfy ride unloaded and the only why to do that is to have a soft spring rate. That is why your truck drops 3", I bet this new Ford rides a lot better then the old Chevy did empty right? Can't have your cake and eat it to.
Has I said earlier, launch shutter will take out your u-joints and carrier bearing and do it in very short order. So you will need to make a decision on what you are going to do to address this or look forward to drive train repairs to the tone of $500+.
The more you tow with it the sooner you will be repairing the truck. What is the drive train coverage from Ford? 5yr/100K miles? If you plan on selling it before 100K Ford can replace the u-joints and carrier bearing under their warranty.
Don