First and foremost, I want to say that this is NOT, repeat, NOT, a slap at the couple of nuclear war threads we've had here recently, especially Macragge's, which I consider probably the single best-written piece of alternate history I've ever seen that wasn't written by a professional writer.
While they were brilliantly written, however, I've taken disagreement with some of the positions he and others have taken in that and other threads.
Speaking from my personal knowledge and of unclassified sources (retired Colonel, USAF, most of my career in SAC) I wanted to address a few of these things.
(1) The Soviets viewed their arsenal as defensive and never would have attacked/used nuclear weapons unless the United States/NATO had already done so.
Sorry kids, but not true. While the bolt-from-the-blue "OK, this seems like a good day to launch an all-out nuclear attack on the United States" attack was always very, very, very unlikely, the Soviet idea of what is "defensive", and ours, were two different things. For example, if circumstances had led to a NATO-Warsaw Pact war in Europe, and the Soviets felt that they were on the edge of victory, and either felt or got intelligence that the US/NATO were about to use nuclear weapons, it is VERY likely that the Soviets would have struck with those weapons first.
Also, the Soviets did not share our beliefs/illusions about such an exchange stopping at a tactical level...it is quite possible, and even more that their initial use of tactical nuclear weapons in Western Europe would have been combined with a strategic nuclear attack against the US and other nuclear powers in NATO, at least in the case of the USA an attempt to take out our land-based deterrent.
Note that I'm not saying these would have been wise actions, or guaranteed of success, by the Soviets...but that was their strategic thinking at the time (~1980-85).
(2) "The Soviets wouldn't have launched a first strike because only half or so of their missiles would have worked/not malfunctioned/etc."
Sorry, not so. While Soviet technology in these, and many other areas at the time, wasn't the equal of ours, it was quite capable of functioning at more than an adequate level under those circumstances. I believe Macragge used a figure of 75% in his thread, which is a little more like it but is still on the low side. The figure we most often used among ourselves in strategic thought and planning during that time period as an estimate was 80-85 percent for Soviet missiles, and 90 percent for ours, or strategic weapons operated by NATO allies (Britain/France). Personally, I feel the Soviet figure would have been around 85 pct, with ours between 90-95, but I would have been on the high end of what other people were thinking at the time.
I've got a lot more, but I want to split this up into easily digestible-responed to chunks

. I'll be back with more in a bit.