Pulling in reverse is not the best of idea's. It puts a ton of stress on the front (axle) u-joints. Yes, they are dana 60's and pretty damn strong... . but a steering 60 is nowhere near as strong as a non-steering (rear) 60. They have broke in the past, and will continue to do so when abused enough.
The reciever pin is fine. In fact, most of the people I hang out with off road just use the pin through the closed loop on a tow strap (push the loop end of the strap into the reciever, put the pin through the loop). I have never seen or even heard of one fail. On the other hand, I have seen towstraps that have hooks on the ends fail... avoid these straps, they are dangerous (in fact, most organized off road groups will not allow these to be used on any run they organize or sponser).