Yes, if necessary. However, it is preferable for Jews to pray in groups (called minyanim).
Many of the same things that other people do when they are alone.
they were punished or were killed. none who helped the Jews were just left alone.
Thousands of Anti-Semitic Laws have been introduced in hundreds of different countries. They did things as varied as give housing restrictions for Jews alone, to expulsion of Jews, to professional restrictions for Jews alone, to marriage restrictions, to forcible conversions, etc.
Yes as the Jews failed to heear the prophets warning.
They most certainly did not act alone. Some countries even paid the Nazis to take their Jews. In France the rounding up of Jews was done by the French police and the transportation done by the French railways.
It made the Jews feel alone and marked. It also made them easily identifiable to non-Jews and led to the two groups becoming more separated.
Whenever they want to. Private prayer is not dictated by Judaism.
In my opinion the Jews did distract him because that's more people you had to have your men keep an eye on, when he should have had those men fighting the allies. I think he could have lived longer if he would have just left the Jews alone and dealt with his enemies, but you have your opinions so right them.
Yes. Jews alone constituted 6 million dead. All of the other minorities (Gypsies, Jehovah's Witnesses, Slavs, Communists, etc.) combined total 5 million dead.
Hitler was the one mainly responsible for the killing of the Jews, but he was not the sole responsibility as all the people who supported him and carried out the killing tasks Hitler set them also shares some of the responsibility.
When the Jews were trying to get Palistine from the British who conquered it in WWI, somebody (?) said, "Even if you get a country of 1 millions Jews, 200 million Arabs will never let you alone". The Arabs held the Jews in utter contempt. Nothing has changed lately.
"la rafle du Vélodrome d'hiver" (the Velodrome roundup) was organized in 1942. The collaborationist government Vichy had consented to the operations on conditions that French Jews be left alone by the Nazis. The result was that 13.152 Jews, out of more of 27,000 registered foreign Jews, were rounded up in Drancy, north of Paris.
There are occasions where Jews worship alone, but these are rare and are generally to be avoided. If it is possible for a Jew to pray in a kehillah (congregation), this is greatly encouraged. Many of the most important Jewish prayers and religious functions (such as the Kaddish prayer or the Torah Readings) can only occur in the presence of a Minyan (10 adult Jews).