Can you use a few of the leaves that were from the prior spring pack or are they the wrong size? I doubt I will shorten one as far as you have yours, but I'm sure the cornering is vastly improved. Every time I turn mine in my gravel drive, I notice the inside tires chewing up the gravel. Makes me wonder if there is a posi-lock feature, at least on the back. At some time I'll delve into the TM to see. I went and looked and your right about the anti-lock brake sensors, they are on the rear axle, not the intermediate (solves that).
As I need a dump truck and the ones on GL seem to go for a premium, I'm having second thoughts about using the one with 11.00's to shorten and bob. I read a thread that says the 11's are better for hauling heavy loads.
Re rivets, I purchased the steel from a bridge recycle some time ago and have had to deal with rivets on steel I want to use in other projects. It may sound rather crude, but I have been cutting them out with a torch and have developed a way that seldom makes a problem for reuse. I take the head almost off, but not far enough to get into the steel below it. Then I heat in the very center and start a blow hole. Can't be timid at that point or it blows back in your face (why I use a full face shield and helmet). Once a hole is established, continue to the rivet sides, but being careful not to go too far. However getting a slightly larger hole is not a problem normally, as I'm usually using a larger bolt or welding. But it throws hot metal big time and one must have plenty of sheet metal guards in place to protect wiring, lines tires and all. I used to go the more cautious route like you do, ending with a punch out, but found any damage I did to the hole was quickly remedied with a larger bolt. Now I torch a slightly larger hole just for that purpose. If I didn't maintain a tip for a straight cut or starting a blow hole, I wouldn't do it that way. A pointed chipping hammer takes off any slobber. Just my 2 cents on rivets.