of the third ring is gone out of this earth, the Great Teacher will have to get reincarnated on the next planet. Only, and since He sacrificed Nirvanic bliss and Rest for the salvation of his fellow creatures He will be re-born in the highest — the seventh ring of the upper planet. Till then He will overshadow every decimillenium (let us rather say and add "has overshadowed already" a chosen individual who generally overturned the destinies of nations. See Isis, Vol. I, pp. 34 and 35 last and first para. on the pages).
(3) Is there any essential spiritual difference between a man and a woman, or is sex a mere accident of each birth — the ultimate future of the individual furnishing the same opportunities?
(3) A mere accident — as you say. Generally a chance work yet guided by individual Karma, — moral aptitudes, characteristics and deeds of a previous birth.
Decimillenium refers to 10,000 years.