Depending on the suspension mods done when lowering, it makes for a bumpy ride, especially when towing. The springs they chose play into it, as most drop springs are progressive, meaning its probably going to bottom out if you hit a big enough bump. Try not to load the tongue too heavy, but don't load too heavy in the rear or it'll sway like crazy. I'm sure you know how to center the load. The bigger wheels may add some more weight to get up to speed but nothing major as far as braking performance suffering. If they trailer has electric brakes and you dont flat foot it, you'll be fine. Take it easy on the hills, slow down if you have to, and watch your tranny temp gauge.
I've towed a larger enclosed trailer with my 04 Tahoe, it was loaded pretty heavy and I've got a 2/3 drop w/20's. I felt every damn bump in the road because of my rear springs pretty much bottoming out on everything lol. And it struggled to stay in 4th gear on any sort of incline, but I just slowed down and took it easy. The stock tranny cooler isnt worthless imo...I bet it helps compared to no tranny cooler at all.
Hope this helps...I'm not interested in the drama.