Well, after the techs at Mercedes finished diagnosing the problems the following is what they found.
Engine miss was caused by a deteriorated main engine wiring harness (ouch! -- the cost of this part is $636 and $575 in labor to install). Appealed to Mercedes for a "Goodwill" warranty repair and Mercedes agreed to cover half of part and labor. As has been discussed on this forum, this is one of the weak points of 94-96 C-Class and E-Class vehicles where wire insulation drys out, cracks and breaks off. In my case wire insulation was cracked and was holding moisture causing occasional engine miss and check engine light to come on.
Steering vibration was caused by a broken belt in the drivers side rear tire along with out-of-round tires in front. New tires all-around together with 4-wheel alignment solved this problem. Also steering damper was becoming weak and leaking oil so refreshed this item also.
Thanks everyone for your comments!