Wow -10 pages of debate. Feeling safe is a subjective thing. Many feel like the Factory Door sticker is a black and white number for safety. Without knowledge of underlying component values, warranty/service life/1st retail sale certification requirements, and your home state regulatory/statutory environment regarding licensing/payload carrying, it would be easy to have a black and white opinion about truck payload/towing capacities.
I tow with a 06 chevy 2500HD SB EC 4wd diesel. Trailer is a 30.5', 14,200 GVWR toyhauler. Pin is 18-20% on a typical trip. Trailer typically weighs 13,700-13,900 fully loaded. Truck is licensed for 10K weight, has heavy autoslide hitch, has air bags to help with sag(not much PSI used), MaxBrake Controller, (prodigy/P2/P3 were all horrible mistakes) and one size bigger LR E tire(1T SRW size. Totally legal, tows like a dream and stops very well. The electric trailer brakes are well sorted out -wiring is proper size for amp/voltage load and regularly adjusted. Typical driving conditions range from major urban area to National Forest/BLM single lane dirt in the Washington, Oregon, Idaho region. Only additional modification I would like on my truck is an Pac Brake exhaust brake for steep descends found off the Interstate highway system. Like White Bird Hill south of Grangeville, Id and the descent from Idaho 20 to the Pine/Featherville area, as examples, just for more braking capacity/margin of safety.
I will also add that "safety" always begins and ends with the "loose nut" behind the wheel..... I travel I-90 for 2x20 miles every day east of Seattle into the foothills---- the amount of vehicles in poor condition and or towing with bad set-up(tail high, tail low, no sway control, excessive speed and tailgating with sudden violent lane changes is amazing.... Many are oblivious to their surroundings, their equipment condition/setup, plus the needed driving skills with a trailer in tow.