About the "mutinious" Imperial Russian Army. The mutinies of 1917 weren't limited to Russia. The French and the Italian armies suffered from large-scale mutinies in 1917. More than fifty French divisions on the Western front took part in unathorised demonstrations of varing intensity after the failed Nivelle Offensive. Most of them simply refused to return go back to the frontline; part of the Second Italian Army surrendered without a fight at Caporetto later that year.
In both cases Allied authorities blamed pacifist and Bolshevik propaganda for promoting rebellion, but, in fact, the mutinieers were more concerned with personal safety and comfort. The soldiers weren't too keen to attack when victory seemed impossible and slaughter was more than possible. Even the British had their own mutiny at Etaples in September 1917! Of course, the circumstances were quite different to the Russian ones. Or not? The British muttiniers complained about the poor conditions at a local camp.
The disintegration of the Russian army, in some sense, reminds me of the fate of the Austro-Hungarian armed forces. In both cases, but specially in the Imperial Russian army, it was fuelled by terrible physical conditions, militar failure and a chronic shortage of supplies (specially acute in the Russian case, to which I would had a shortage of good NCOs and officers). The only difference, the one which mattered in the end for both Empires -at least for a while- is that while Vienna had an Ally to back up (well, or to dictate her what to do) her -Germany-, Russia was isolated from her allies, which could not help her in the right way.
The Imperial Army betraying the Tzar? The soldiers were tired of war and of being wasted. The officers hardly could keep their units under control -or t hey simply couldn't and got shot. If the Army rejected the Tzar it was due to the fact that they had lost their faith in Nicholas II.
An interesting reading about this is John Erickson's book The Soviet High Command 1918-1941. It gives a good picture of how remnants of the Imperial army became part of the Red Army.