The manual says that the bumper is designed for a 3500lb trailer and a 350lb tongue weight. I'm willing to give Nissan's engineers the benefit of the doubt on those design calcs
I wouldn't hesitate to tow a small, carefully loaded trailer as long as you're positive that the total weight is less than the max (I'd shoot for a max of 2500 myself).
However, if this is something you're going to do fairly often I would definitely install the receiver hitch. It's a simple bolt on install and you can get the hitch for $100-$200.
With the receiver hitch it is easier to get a ball mount with the proper drop so you can match the tongue height to the ball which may be important depending on if your truck is stock or lifted or has larger tires.
Either way you're going to have to install a plug for lighting and from what I have seen the Nissan wiring kit is the way to go since it contains all the proper relays and plugs and is a plug and play install.