I got old school Rancho 9000s on the Warn Pinz. A few weekends ago we could feel the shocks fading while doing our little high speed stuff. I don't know anything about the rear shock bolts breaking so will just take your word for it.
As far as performance, a bypass will always be best for that regardless of use. They are tunable by the way and rebuildable. Do most people need them, doubt that. But most people also don't need a Pinz as a toy.
Here is some less priced King's and the shock you linked is a high performance triple bypass that would never fit under a Pinz plus it is a 16" travel shock. For what it is, it is a good price!
http://www.polyperformance.com/shop/Kin ... 30180.html
and a non-bypass
http://www.polyperformance.com/shop/Kin ... 30178.html
I have no idea if these would fit on a Pinz. More than anything I was just curious. I have ran Icons and Ballistic bypass shocks before and also used Bilstien non-bypass on different trucks and was happy with all of them. In the past I have always flexed a truck up with no shocks, taken measurements and then went shock shopping. So far this method has not failed me and I simply hate the low end shocks that come with lift kits and so forth. In fact I have found a lot of these shocks included in lift kits to be the wrong lengths! On a Pinz, I suppose most of this does not apply!
I am sure there are others who like to go fast in the dirt in their Pinz, they probably just are not talking about it much. Not sure how you couldn't enjoy it, the trucks handle very well and IMHO excel in this type of driving. Plus that old school factory video shows the trucks being used just this way as well as in deep water, mud, ect ect ect.