Do you think it is necessary to attack Europe using medium and short range? Why exactly, can you elaborate?
It would make more sense to hit all cities at once with nukes (there are no nukes in Kaliningrad).
Why would the Russians hit all cities at once with nukes? If it ever got to that stage, there would be no winners.
I imagine any major missile attack would potentially include conventional, chemical and nuclear warheads. It all depends on the scope of the operation. A mass attack against NATO in Europe would include 100's of potential military targets; and I don't believe the Russians have that many nuclear capable missiles that they could deploy, without them needing to mobilise the warheads they have in reserve. Thus, IMHO, any initial nuclear attack against Europe would more than likely be aimed at key bases and military concentrations in Eastern Europe using tactical nuclear warheads, or low kt warheads that could be deployed on the Iskanders.
There are currently - according to the Russians - no nukes in Kaliningrad. But it would not take them 24 hours to fly them in.
Long range missiles (ICBM's) would not be used against European targets. Most of - if not all - of the Satan 1's and 2's would be used against the US in any type of nuclear exchange between the two powers (The ICBM force is primarily a first strike weapon used to destroy or incapacitate the enemies nuclear forces).
I am not that up-to-date with the accuracy of SLBM's, but I believe the Bulava has good accuracy in comparison to the Trident; and IMHO, would be used against European targets.
This is, of course, conjecture on my part. I sincerely hope it stays that way.