Sitting level as I assume you are with 3" drop your headlights should be of no concern to oncoming traffic. But sounds like yours are a problem. Take it to the dealer and have them adjusted with RV in tow.
If you add air bags and raise the rear to unloaded height when hooked up you will have a very harsh ride.
I added air bags to my 3500 dually even tho it sat level with 4,500# pin weight. The reason I added them is to smooth pout the rough expansion joints. I run them at 5psi empty and when hitched it increases the psi to around 30psi. Makes no difference in ride height but sure helps smooth things out.