One thing many participants in this discussion have ignored is that Hitler surrounded himself with people who would listen to Hitler's rants then try to put into action those rants by the most radical means possible in order to curry favour with him. Hitler also encouraged his officials to fight amongst themselves to achieve what they saw as Hitler's wishes.
The Holocaust could've been avoided if there had been a few more pragmatic Nazi officials like Werner Best who rid Denmark of its Jews by tipping off the local authorities and turning a blind eye as the Jews crossed over from Denmark to Sweden and there had been a lot fewer people like Hans Frank, the Nazi overlord of the Government-General, whose answer to ridding his part of Poland of Jews was to exterminate them.
The other thing that could've avoided the Holocaust would've been if the local non-Jewish population had put up more resistance to the deportation of the Jews. Without the co-operation of much of the local population, the identification and the rounding up of the Jewish population in the Baltic states, France, Poland and other countries would've been virtually impossible because the Germans simply didn't have the manpower to do it themselves.
As the old cliche goes: "Evil triumphs when the good do nothing."
I won't speak for Poland or other countries but you're right about France, at least partially.
The Vichy Regime was not only a collaborationist entity, but also a counter-revolutionary regime which sought after the eradication of all symbols of the Republic and all people individually or collectively associated with the Republic, including Jews, since Antisemitism is a component of the French far-right ideology since 1875 at least. That's why Vichy, not only helped for the deportation of Jews (foreign Jews at first, but the French, assimilated Jews would have encountered the similar fate sooner or later), but initiated collective measures, including massive round-ups, before the Nazis asked for them. The infamous Rafle du Vel d'Hiv in 1942 is now a documented evidence of this.
However, the majority of French people were, at worst, indifferent to that policy and, at best, quite hostile to it, especially after the entire territory was occupied in late 1942. While many foreign Jews, especially children, have been hidden in farms, in Catholic or Protestant institutions, or by individuals, many ordinary people didn't felt like reporting their Jewish neighbours of refugees to the police. Inside the Vichy administration itself, some policemen or Gendarmes warned the Jews that a round-up would take place so that they could escape. That's the main reason why more that 70 % of the Jews living in France in 1939 survived the Shoah. Of course, France was not suffering a brutal, direct Nazi administration like in Poland. The country was also far less urban than, say, the Netherlands, and offered many places to hide in the countryside, in the mountains...