Well, you're showing 11,200 lbs. on your truck which has a GVWR of 10,000 lbs., so you're over your truck GVWR by 1200 lbs. And that will go up a bit more when you add the 1200 lbs. of cargo, unless it's all rear of the axle in which case the pin weight might go done some. You're over your rear axle certification rating by a couple hundred pounds, which will also go up some when the trailer is fully loaded unless as noted.
You're pulling a 5th wheel that weighs about 13,000 lbs. and you're going to add about 1200 lbs. to that. Your GCW will be around 23,000 lbs. so you're under your GCWR.
What tire size/rating are you using? Isn't the Denali an SUV? We are talking about a 5th wheel trailer here aren't we?