The tsar Nikolai had his day at Stavka good organized, and organiyed in such a way he alterned work and rest. Every morning he attended the "doklad" at the Headquaters and, as testified Spiridovitch, he was not only listening, he participated and decided. According the same he had good knowledge of the cards, of the military situation of the moment. Fact is that there was not so many military desaster after Nikolai II took th commandement. The tsar physically needed walk and fresh air and he manage to walk 2-3 hours every day. Probably found he in it new forces and new inspiration for his work. He was reading all the paper himself, one can say it was not necessary and he cold have had a secretary. That is true and my guess is he tried this way to prive other and himself he control personnly all. Anyway, it was his style of work (every ruler has his own style), he did hi daily work and was in course of all. Another thing is that he was in 1916 certainly extremly tired and under pression which, from my impression, is one of the reason for this strange decision of abdication: to tired to fight against treason.
About Alexandra's power, she had no official authority to decide, only Nicolas II decided. But the same Spiridovitch in his work about Great war and revolution of february suggests interesting things. Well, sorry I must deal with the weeping and screaming children... Perhaps Belochka will carry on or someone else.