I think you will find that ARB has been around for a long time and have satisfied customers around the world. You can actually have some of their bumpers added as original equipment from the dealer in some locations...
Also if you know anything about Euro standards as well as Australian road standards to be certified for the road they have to meet strict crash and protection standards. they are also designed and tested to work in conjunction with your original equipment safety gear...
Feel free however not to like them, but to be intellectually honest you cannot question their mfg or safety standards...
Its a great medium to light duty bumper, but most of the Euro/Austalian trucks running ARB bull bars use separate recovery points bolted to the frame.
They will work just fine in a car accident which makes them useless for serious offroading.
I still dont think you have anything to worry about when it comes to your radiator. As mentioned I would address your lack of diff cover before worrying about a skid plate..