With a car having a unibody construction, there is no doubt that you can cause damage, the GV with its integrated frame should be ok, but too much weight on the back is not too good as you loose weight on the front and impair your driving.
Last summer I did around 2000 miles from Montreal to the US NJ east cost with a tent-trailer, we were really loaded inside the GV, the tent-trailer was around 2200 lbs, unbraked. Braking power was enough. The GV had enough power going through the Adirondacks and Cat Skills mountains. Most of the time it remained in 5th gear with some few times in 4th and very few times in 3rd at the top (2 or 3 times). Gas consumption with the V6 was impressive with an average of 12.5 l/100km at around 115 km/h with AC on all the time.
My guess is having a 3000 lbs trailer would probably have been painful for the engine.
The weight on the tongue was around 250 lbs, and on our way back we had at one point cross winds with peak up to 80km/h. To keep good stability on the front wheels and direction, 250 lbs on the tongue was near the limit, more than this would have been almost dangerous. I would suggest that if you think that you’re going to put more than 250 lbs on the tongue (and having people sitting in the back with some stuff in the trunk) to go with a weight distribution kit, which I will most probably get next summer, for a more level ride, greater steering, and help in braking control.
Compare with my previous Jeep Cherokee (XJ model), power and torque was almost comparable, a little advantage to the Jeep, gas consumption was better on the GV, comfort was better on the GV, braking power was more powerful on the GV, steering was better on the GV. I did add a leaf spring on the rear suspension of the Jeep, which I cannot do on the GV, this is why I will probably go with a weight distribution kit.