Just a thought about your low speed clunk or whatever it is - check that the subframe bolts are really tight. I had a clunk at low speed and that's what it turned out to be. I didn't torque them I just got a breaker bar and tightened all of them with some sensible force..
As for the shimmy I chased a similar thing in mine for years and it didn't go away until I had a new set of tyres fitted 6 months ago. I had wheels balancing done, poly bushed the thrust arm etc but nothing changed. Brake caliper rebuild (easy peasy) was also done to eliminate them binding.