Titan owner here.
I also think that this trailer may be a bit too much for your truck. The Titan is an excellent platform, but with limitations. Payload is the big killer on the Titan, especially in the crew cab configuration. (I assume your Titan has the Big-Tow package. Tow mirrors, trans temp gauge, etc. It IS pre-wired for a controller.)
"Dry" weight (if known) is unrealistic measure. When it comes down to it, the trailer must be weighed. Anything else is speculation. Hopefully the previous owner did this sometime, but it sounds like he hasn't. Case-in-point, my 2006 Jayco 29FBS had a "dry" weight of 6725. Once loaded for the road, it scaled at 8000. (Gross is 8750 btw)
In my opinion, I would not tow anything much heavier than 8000 with the Titan. Can it be done? Sure, but the driving experience may be less than pleasant. Don't expect too much with mileage, my tow mileage is between 8-10 mpg depending if it's mountains or flats. The engine noise someone mentioned is not that big of a deal, 3-4000 rpm under load is no sweat for the VK engine. 5K+ is a different story. Noisy.
Feel free to PM me with questions!