I’ve never had insurance (or tags) on my E30. I bolted everything on and tested it all at once this past weekend at Rockingham. Prior to that, I had never taken the car to red-line or even exceeded 40 mph in it. Thankfully, everything worked.
What I did was cruise through my neighborhood at low speeds and make sure I had no vibrations or weird sounds, and that the brakes, steering, and clutch all felt normal after I made changes to those systems. Hopefully you can at least get away with that. The street into my development dead ends so there is not a lot of traffic and I felt very comfortable and safe doing this. The only problem this method exposed was my upper spring hats contacting the camber plates - easily solved with a thicker spacer.
The only things that we can really change performance wise is suspension, brake pads, bushings, and exhaust. I’ll bet you can get most of the answers you need by one of the follwing: tooling around your neighborhood (if you can get away with that), the alignment rack, the dyno, and lastly by taking it to the track. The track is where the real answers are anyway.
Based upon my experience, I say go for it. Worst case, load the car up and take it somewhere you can test the changes you have made (country road, private parking lot, etc.).
Steven
PS - sorry to hear about the truck.