Yes, you can do it safely. I suggest a really good load distribution hitch, but yes even without one it can be done safely with air bags like the Air Lift 1,000 unless you're getting one with the air bag system OEM. You just have to make sure your trailer brakes are always in perfect working order, and that they can do at least 51% of the braking. If you see heavy dust after each use you need to advance the trailer brake controller gain by 1 until you can stop the trailer from 10 mph within the combinations own length.
I used to pull my boat which is about 8,000lbs on its steel trailer that's about 4,000lbs, 12,000 combined with an '07 Durango with 3.92 gears with the hemi. Yes, I know how dumb this was now so no need to comment on that. Fact is it pulled the boat better (better power to weight) the 04 RAM 2500 4x4 with 3.73 gears and the hemi. And it pulled it out of the ramp better too, and, got considerably better fuel economy doing it. It just got pushed around occasionally.
I don't recommend going that far over numbers, and, I don't really recommend going across country with more then about what you have. But it can still he done safely if you keep your speed down, keep a distance between you and the vehicle in front of 1 second for every 10 feet of combination length, and above 40 add an extra second for each 10mph on top of the 1 sec per foot rule.