Our camper is about 4500 lbs. ready for 2 weeks. Tongue weight is 552 lbs. We have the Andersen Hitch. I can hit 65 mph long before merging on most interstate ramps. Been over the Rockies and all over the Appalachians with nary a problem. We get 10 mpg average. I have never felt unsafe nor had a white knuckle moment with our Frontier, but I'm meticulous with weights, tires, following distance, etc.
I do turn off OD when towing and manually downshift when necessary.
Our son has the same truck and virtually the same camper. They've never had a problem towing, either.
Understand and pay attention to the numbers and you'll be OK.