Given the short narrow wheel base of the Bronco 2, I wouldn't want to be towing much with one at all 2k is a lot of weight and will definitely push the B2 around especially in a cross wind or from a passing 18 wheeler.
To figure what you can tow, you need to add up all the weight that you will have in the B2 including yourself, passengers, gear, fuel, as well as the tongue weight of the trailer, etc. Then subtract that from your gross vehicle weight. That will tell you what you can tow. I bet its far less than 2000lbs that you will be able to still tow. Basically its a vehicle to get you from point a to point b, its far from being a tow rig.
I was reading somewhere a while back and someone mentioned you can tow up to 3500lbs with a regular tow hitch receiver with a Bronco 2, I just laughed at it, poor thing can barely manage to move itself around.
With just using the bumper as your hitch, I really wouldn't want to try towing much weight at all with it, its just not meant for the sudden weight shifts that will occur stopping, starting, cross winds, etc.
