To do the tie rods etc, the battery should not have been unhooked. If it were...it would relearn everything over time which it kind of sounds like. The sand sound you mention..I'm almost wondering if that's knock that you are hearing. You are using 91-93 fuel all the time correct? Knock might be loud enough to hear and would reduce power. It's odd thought because you seem to know about these cars and their quirks.
I'm unsure why the inspection station would loosen a tire, I've never had one loosen a wheel to do anything. I'd think the mechanic last working on the car forgot to torque the wheel (aka air gun them on.) You've had a bunch of issues going on in the past, some stuff seems to make sense and some doesn't.
