Came across this; it should answer all your questions.
Driver and Vehicle Requirements and the Installation Traffic Code for the U.S. Forces in Germany
From glancing through it the two biggest issues i see are what I mentioned before:
1. Tyres cannot extend beyond the body.
2. Headlight aim due to you leveling kit
If you have tint on the front side windows you need to remove it before you go as well.
If you're still making payments on your truck you need to get written permission from the lien holder to take it overseas.