Read the owners manual. As previously mentioned, many vehicles have max tongue weights that are limited without weight distribution. On my RAM 2500 its 500 lbs max, and 1000 lbs with weight distribution. The owners manual should explain this, or the separate Ford towing guide for the year of the tow vehicle.
WDH helps a lot with porporsing or chucking such as crossing RR tracks and other road irregularities.
Many SUV's come with P series tires and they have soft sidewalls. It might tow a lot better to have a tire with a stiffer sidewall. In any case the rear tires may need to be inflated to near the max on the tire sidewall.
Trailers with torsion axles such as Escape and Airstream need to be as near level as possible when towing. The two axles function independently of each other and nose high will put more load on the rear axle and less on the front, which will increase tongue weight (and help prevent sway) while nose low will leave the trailer on the front axle and the rear axle skipping along with less load on it and making for more sway possiblilities. This is true of leaf spring axles with equalizers but (personal opinion here) to a lesser degree. Axles with equalizers and leaf springs still have some interconnection, while torsion axles are TOTALLY independent of each other.
The big deal with torsion axles being level is you are putting a lot of wear and load on the elastomer in one of them, with leaf springs and equalizers you are not significantly overloading or harming the springs.
This video helps somewhat I do wish he had used a dual torsion axle for the demonstration.
Charles