The strut rods locate the LCA fore/aft, not the bushings. Pressure from the tire isn't even a part of it, that wouldn't work for one second with the car in motion. Those directional forces are constantly changing as the suspension works and the wheels turn. There is no need to shim the torsion bar, that's just completely ridiculous.
The OEM bushing would tear in a heart beat if it was what kept the LCA from moving backward. Even with all OEM bushings, the strut rod is what keeps the LCA from moving back too far and tearing the OE rubber bushings, that's why the factory put them there. The rubber in the LCA bushings would just rip right out without them. Rubber bushing material does not keep the LCA in place. Think about that, you're asserting that the rubber in the LCA bushing is structural. That's ridiculous.
You can absolutely install poly LCA bushings incorrectly. The picture you showed is a perfect example. That LCA is not in the proper location, and likely that's because the strut rod is the wrong length. If the LCA isn't fully seated against the lip on the LCA pin then the installation is wrong. Period. It would be no different than pressing a rubber LCA bushing half way onto the pin and running it like that, it can't function properly that way.
There's absolutely a procedure for installing poly LCA bushings, and it's not the same as the OE bushings. They must be lubricated, because unlike the rubber bushings the poly bushing must rotate on the pin so the LCA can move. There's almost no flex like the rubber bushing depends on. Because there's almost no flex, the strut rod length is much more critical. The OE rubber set up is more forgiving, but all that flex is slop in the suspension. Properly installed, adjusted and tuned poly or Delrin bushings will last longer and provide better handling. Installed incorrectly they'll fail just like if you install the rubber bushings improperly.
