Sorry, I meant to say springs. With new shocks and
springs, your ride should be very close to new regardless of bushing condition -- except for small bumps as you mentioned
Very tired today.... You will notice a substantial difference handling small bumps with 4 new front sway bar bushings in place. After that I'd replace the steering damper (little shock absorber in the middle) if it's still the original. Very easy to replace too.
Yes, those mounts in your engine bay are supposed to be rigid -- you may want to check to see if your shock "bump stops" were replaced with the shocks. They are mini rubber cylinders mounted on the top of the shock arm itself and protect the shock cylinder from hitting the top of the wheel well - but these would only help you with large bumps .... you said your suspension isn't taking small ones well
Another question: what brand shocks did you replace the originals with? I hope you used Bilstein
'91 300E, 211K miles