1) Yes and no. There was a plan to send “racially pure” jews to Palestine.
Some German jews, mostly ex-military, were indeed sent. Many of these joined settler battalions, becoming the Irgun and Stern Gang.
Slavic jews were specifically singled out for extermination. Alongside of Slavic christians, atheists, muslims, and buddhists.
The same was true for Roma of all religions, who were deliberately categorized as “subhuman vermin” and slaughtered.
Other jewish populations were exploited as slave labour, and many of them died from exposure, hunger, disease, and casual violence of their masters.
2) No. The deliberate gassing of captive Slavic jews was indeed a policy.
Also the gassing of western jews deemed too weak or delicate to be useful as slaves.
In addition… the massacre of Hungarian jews as reprisal for the assassination of Heydrich, claimed over a half million victims. Most of whom were gassed in camps like Auschwitz.
3) The exact numbers are less important than the fact that it did happen, and why it happened.
Was it six million? I don’t know or care. What matters is that some people decided that other people were not people, and treated them accordingly.
The sheer scale of the killing was insane.
The wasteful policy was driven by ideological fantasy of “race”.
That the English speaking countries refused to receive refugees fleeing from Germany in the 1930s, is a shameful and disgraceful episode of our history.