In a word, the answer to your questions is “no”. You’ll have to pardon me if I don’t feel like addressing questions 1, 3, and 4 at this time.
For the following, I’m relying on a recently published account of the Kursk disaster, Cry from the Deep: The Submarine Disaster That Riveted the World and Put the New Russia to the Ultimate Test (Harper Collins, 2004) by Ramsey Flynn, a freelance journalist. It details a wealth of evidence that the Kursk disaster is emblematic of a system which assigned safety the lowest priority, in which dangerous, outdated, poorly designed, and under-maintained weapons systems, ships, safety equipment, and recovery vessels collectively guarantee such disasters in the Soviet-cum-Russian navy. Further, these hazards are greatly exacerbated by failings and incompetencies in the communications-command-control structure of that navy, which in the Kursk crisis obliterated what slim chances the 23 survivors of the blasts had for a timely rescue.
A key chapter re. your inquiry is Chapter 4: “Dangerously Late”. In it, Flynn goes into great detail about the Soviet Type 65-76 Torpedo, aka “tolstushka,” aka the “Fat Girl”. It’s a 4.5 ton, chemically unstable 85%-strength high-test hydrogen peroxide [HTP]-propelled, 1976-vintage behemoth which requires dedicated maintenance and storage procedures, lest it spontaneously self-destruct.
Torpedoes which use the HTP oxidizer system for propulsion have the advantage of superior propulsive power and striking range, but at a terrible safety cost. The Brits and Americans both ditched this type of propellant for their torpedoes “by the 1970’s,” according to Flynn, after both navies suffered at least one accident involving the spontaneous detonation of HTP torpedoes back in the 1950’s. Nor was this type of disaster unknown to the Soviet navy.
The Fat Girl was designed to have a 20-year lifespan, requiring a complete overhaul every ten years. This, and a great many other regular maintenance and safety regulations were neglected as the U.S.S.R. crumbled. In the 1990s, Russia’s President Yeltsyn slashed their military budgets by an incredible 95%, IIRC. The particular Fat Girl that was sloppily loaded onto the Kursk (the inadequately-maintained torpedo loading crane nearly lost its hold on it during loading, and the torpedo was roughly set back on the dock before it was successfully loaded onto the Kursk) before its final journey lacked the requisite paperwork demonstrating sufficient maintenance (“many chain-of-custody signatures were simply missing – with little or no indication at all that the torpedo had received its proper midlife overhaul”).
Furthermore, when the Kursk got underway on August 10, 2000, it had only one man on board who was familiar with the Fat Girl torpedo. Normally there would be at least four personnel with such expertise, but due to a freak series of incidents, none of the regular crew with Fat Girl expertise were available; the lone officer with that experience was dragooned for this mission by the Kursk’s captain; the officer in question was due to start another job and undertook this final mission as a personal favor to an old friend and mentor.
And if all this wasn’t enough, the Kursk itself was an ongoing experiment in improvisatory repairs and intra-fleet cannibalization, courtesy of parts supplied by its sister sub, the Voronezh.
The evidence as laid out in this book is overwhelming that the Kursk was destroyed by the accidental detonation of one of its own torpedoes, which set off a fatal chain reaction in which at least four other torpedoes detonated two minutes and fifteen seconds after the first blast. The Russian naval exercises in the Barents Sea were well-publicized before the fact, and it’s true that American and Norwegian surveillance was active on the scene, in the form of both deployed crafts and high-tech buoy arrays – however, at the time of the accident, the nearest American submarine (the U.S.S. Memphis) was some twenty-five miles distant from the Kursk. The conspiracy theory that the accident resulted from an unacknowledged collision with an American sub was propounded in particular by the Russian Defence Minister, Igor Sergeyev. This theory was decisively refuted by the 33-volume report on the Kursk disaster prepared by Vladimir Ustinov and released in July of 2002. The Ustinov Report concluded that the Kursk was doomed by a leaky “Fat Girl” warhead-less torpedo, type SS-N-16, product number 398. The likely leaks occured through microcracks in the oxidizer tank casing (a danger well-documented with torpedoes of this type). When the HTP made contact with certain metal parts inside the torpedo-firing device, the instantaneous detonation produced a force of “50,000 atmospheres,” igniting a fire in the torpedo room and blowing out the double-hulled walls of the sub. Metal shards punctured other fuel tanks and ignited neighboring warheads, and the resulting inferno may have reached a temperature of 5,400 degrees Fahrenheit over the next 2:15, at which point the other torpedoes exploded (p. 206).
I think the Kursk conspiracy theory is one that can be safely be put to sea.