People seem to have differing opinions on the value of LT tires. I used them to replace p-rated tires on my last tow vehicle and was glad I did. I don't have enough reason to do that on the new truck, but when these wear out, I will replace with LTs.
I haven't done the Bilsteins, but they are mentioned on here, as well as on F150 specific forums, often.
Those more in the know can certainly correct me, but it has always been my understanding that airbags and WD hitches don't always play well together. It might help a bit with your 'bounce,' but too much airbag support can counteract the work of the WD hitch. Others may have more experience.
One other consideration would be to make sure that you have the right bars on your hitch. If your original set were 1,000 pound bars, you could have been getting by, reasonably, at 1,050. Jumping up to 1,200, however, they may not be able to do the job that's needed.
