I used to have one of those, actually a few, that failed, steel strand snapped and in one case somehow came undone, and cut the sidewall of the tire, it got tossed, now I use one of these (below) I think it was a guy on ADVrider who was making them, not sure if he still does...much better, it has what I'd call an old toilet chain instead of the steel strand
If you're pinching tubes, are you adding a little air before you attack the bead. I find doing tires is technique and practice, if its hard work you're doing it wrong. I change all my own tires including ones with very stiff sidewalls like Heidenaus and Mitas dakar race tires, bad technique will not help you get these on, it just won't happen
Best tire mounting tutorial out there is Ned's
No pinch tool, yeah I had one, used it, sold it, does it work, yes and no, certainly not as easy as they show it, for soft MX tires it makes them a breeze, for tougher tires, not so much because the center wants to raise up. So you are trying to hold the bead in the well with your feet or knees, hold the middle part in the axle hole, and use the handle and rotate it all at the same time, generates as much swearing as tire irons sometimes.
Also its not their original idea it was taken from a guy Ukraine I think who came up with it, and they made it 'theirs'