You mentioned the rear suspension was also a bit uneven. Maybe what has actually happened is a problem dropping the back onto bump stops one side, thats quite a lot of lowering going on , and the front is just following it down. Have a good look behind the rear wheel at the gaps between the suspension arm and the bump stop rubber thing. It could be a broken torsion leaf spring in the front suspension, causing extra lowering on that side, possibly brought on by somebody taking out leaf springs to lower it in the first place. Losing the leaf spring would cause it to just lower, without any wierd steering/knocking/wobbling effects. Quite safe apart from slowly cutting the tyre on bumps. It could be a broken rear torsion bar (hence the idea of checking the back end for problems) . Of the two I would prefer the rear torsion bar as you can get at it fairly easily, the front is a much more involved job. As for the metalwork there, the wheel arch consists of two metal pressings spot welded together with the join facing the endless spray of water off the wheel. Once they come apart or rust breaks out, its on the steady trail to a new wheel arch section.
If thay are like bugs check the front opposite side. If the front beam is not the same side to side (left to right) the back end will show it. Bugs are shorter so you see it more
You stopped at Warwick services? I'd say you've got an illegal stowed away on that side and quite a big bugger at that. Call plod asap.
Van stance. It’s always seemed to sit high at the front. I’ve looked underneath but can’t see anything obviously awry.
They’re supposed to be higher at the front, so when the driver gets in it levels off. (Not in your case obvs).