That is an awesome Truck and a nice trailer. You will be fine if you are careful and take your time. If you just stay on your game just like every normal person that is towing SHOULD, and use extra caution around those tricky situations, you should be fine.

I would definately use the tow/haul and let the thing tow in OD if it wants. There is NO REASON to not use OD as long as the trans is not hunting and as long as the converter stays locked.