Okay. I recommend trying a bonded washer, but make sure it's made of fluoroprene, viton/FKM, or fluorosilicone to ensure it's resistant to ethanol.
Your washer+oring trick will probably work, but if you want something more permanent this should do the job.
The LCA bolt is much easier to align if you use your lugnuts to bolt four LARGE box wrenches to the studs (or lug bolts to the hub) at 12:00/3/6/9. Becomes very easy to horse that hub around, especially lining up the RLCA and/or the last arm to bolt up, which is always the hardest one.
The tuner does not need to be local to you. You can be tuned by anyone on earth.
I personally use Xavier (SumoTuned) and have always enjoyed his responsiveness and results. I'm sure others would have good suggestions, too.
But you can just email one of these options to be tuned.
You will find that most of these are basically identical. Roughly 4K spring rate front, 12K spring rate rear. HKS, Fortune, KW (dba ST Suspension) -- all decent brands.
There's not much to compare except price. They all do the same thing and have about the same specs. They will all be less...
Check the ground for the EKP module in the trunk. It is the little black box with two brown wires going to a metal tab and secured to a post. I had the exact same symptoms as you and discovered that my EKP (fuel pump control module!) was making intermittent ground, as the nut had spontaneously...
My best guess is it's just cavity wax/oil from the factory. When I removed one of the front subframe bolts, there was so much corrosion prevention inside the chassis that it poured a physical puddle onto the ground. I thought I had an oil leak from the block until I realized what it was.
That...