Air bags are nice, and unlike helper springs (additional leaf), can be deflated to let the truck feel stock again when not towing.
WDH are nice, but they work by lifting the center of the rig (at the hitch) to put more weight on the front tires (and rear trailer axle if a tandem axle). This means the truck rear tires are unloaded. This is fine as long as the rear is not unweighted too much. It might take so much lifting force to get the truck level that almost no weight is on the rear. Try driving up a slight gravel slope with a WDH at max and you will spin out easily.
WDH is all about proper balance, WDH is meant to offer some help, but not meant to offer a LOT of help.
WDH will need to be unhooked if you find yourself on uneven dirt roads or roads with dips that will make the up/down angle between the truck n trailer abnormally increase, which will break the WDH springs, or bend the trailer or bend something. Not so with ari bags or helper springs, however.
Remember trucks are made to be rear high when unloaded so that when loaded (as expected they will be, because - truck) the truck will drop an inch or two in the rear. When trying to use WDH, or bags, or springs do not try to get back to the unloaded rear height, just get the truck generally kind-a level. An inch or two sag in the rear is expected, and evens out with the front since it is rear-high when unloaded.
Trailer brakes will be a good idea. My bicycle has bigger brake pads than these trucks, so be glad they are 4-wheel disc unlike the Tacoma's. The trailer should be set up so that it is powerful enough to stop itself, and then the truck can stop itself and not wear out pads / heat up faster.
People talk a lot about length of the trailer. As far as just the motor and trans goes: In calm winds the length is not an issue, actually, the longer the better as a long trailer allows the turbulance created at the front to calm down so it flows off the back smoother. However, in crosswinds (hello Kansas) the wind is actually hitting the side of the trailer more than the front so here length does increase frontal area.
Frontal area is really the biggest factor for towing on flat roads. At highway speed the aerodynamics are everything, and those tall and wide boxes called campers push a lot of air.
Also, if you would tow your camper backwards it would be much more aerodynamic. Having a sloped/ramp shaped front on a trailer is not aerodynamic. It would be better to have a block front and slope/shape the rear of the camper so air flows off of the rear smoothly. Campers with a slanted front are all gimmick and no go. Most of the air will flow around the sides and not over the roof anyway, so the "bull nose" front ends that direct the air to the sides are better and more aero. V-nose are not aero.
Look at all the RVs from the 1950s, when they were trying to be aero like the WWII planes, and you see they are all sloped at the rear. But the buying public is too confused, so manufacturers found they can sell what looks aero more than what is aero.
If you want to be more aero, increase mpg, and lower strain on truck, then get narrow and less-tall (mimmic truck width and height) and keep it as close to the truck as possible.
Keep the corners rounded like the Airstream or the similar fiberglass campers.
A camper shell on your truck will also make the rig more aero by smoothing out the airflow between truck n trailer.
If you plan on just a few short trips (under two hrs) a few times per year, then don't sweat it. However, if you want to be driving all over the country and rack up serious miles, then the Frontier is the wrong truck for anything over a small cargo trailer (narrow, low, light). Get the right truck, a 1/2 or 3/4 ton truck. A 2011 f150 with the 3.7 v-6 is more power and more torque than this 4.0 Nissan and the trans can handle more towing, and the bigger truck will not be bullied around by a trailer quite as bad as will to a Frontier. The Frontier is being reported to get 10-11 mpg towing a basic camper, where an American big truck will not notice it back there as much, a full size US truck is likely to get better mpg. Running the Frontier at its limits WILL wear it out much faster, where the full size truck will be still in its comfort zone and not get such accelerated wear. For the Frontier, I would be fine with a folding trailer, but not so with a full size one