Sorry to break in late. I don't check the towing forum every day...
One issue you may find is that towing a trailer that close to the max rating of the tow vehicle can make for a tiring drive. I've done the rough equivalent of what you're doing (a 24ft enclosed trailer towed with a 05 Tundra, probably about 6K lbs for a vehicle rated for 7100 lbs.).
I found that, while we got the job done, it was a much more fatiguing experience than just driving. There was more attention to traffic, more attention to the gauges and the increased need to anticipate traffic flow. In my vehicle, the trailer made the ride more choppy. On rough roads I could really feel the ride deteriorate. On long hills I dropped down a gear or two to maintain speed - that added to the noise factor. And it clobbered my fuel mileage to where I needed to stop every 225-250 miles.
Do you have mirror extensions? Unless the Pathfinder has tow mirrors that extend out beyond the sides of the trailer, you really can't see what is beside/behind you, particularly on the right. Since I tow in the traffic-choked and narrow northeast, the visibility issues by themselves add to the challenge.
When I add all this up, I find that I'm more comfortable with driving fewer miles per day than I would otherwise. YMMV.