Need Crumple Zone Repair Advice, Repairing LH inner wheel well crumple zone Options

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I'd appreciate advice on how to go about repairing some old collision damage from a rear LH impact that deformed the crumple zone. In the photo you may be able to make out a vertical crease that was previously straightened out just behind the rear strut and going from the bottom pinch seam up the top of the inner wheel well (maybe beyond that....still cleaning out the undercoating).

The evidence that I've found of the impact so far includes:
-The rear quarter/rear of door gap was too tight (maybe 1-2mm throughout)
-Area around the old crease is dented in several MM
-There's a lot of subtle deformation (high and low spots) between between the old crease and continuing forward of the rear strut
-There's some booger welding around the rear suspension console
-There was some deformation of the top of the rear quarter above the creased area (subtle bumps that weren't visible but that you could feel)
-The rear trunk lid was pushed forward, probably breaking the LH hinge pivot (was replaced by PO with a screw-in pivot point and fitted with gas struts to hold lid open)

What I'm wondering:
-How can I tell where the inner wheel well skin is/is not deformed? What's the proper profile in this area (straight, curved, etc)?
-How should I deal with the deformation on the skin of the inner wheel well? Should I remove spot welds, cut it out, and replace it? Or could I get away with pulling out the low spots with a stud welder?
-How can I tell if the impact messed up any of the structure between the inner wheel well skin and the interior of the trunk? What measurement points can I use to tell if that structure has shifted?
-How can I measure to make sure the top of the inner wheel well panel where the rear quarter attaches is at the right height after repair?
-How can I tell if the suspension console is properly located given the impact damage and evidence of booger welding there?
-How the hell did I ever think I was going to get this car on the road by this Spring?